1. A preparation method of a graphene oxide-carbon fiber hybrid reinforced shape memory composite material is characterized by comprising the following specific steps:

first, three-dimensionally printing a base sheet:

step 1, establishing a three-dimensional printing matrix shape in Creo software; the shape is a cuboid of 60mm multiplied by 30mm multiplied by 0.5 mm;

step 2, setting Cura software printing parameters;

printing the base sheet by adopting a layered filling printing method; the base sheet is obtained by layered printing, and the thickness of each layer is 0.125 mm;

setting the moving speed of a printing nozzle to be 50mm/s, the printing temperature to be 210 ℃, the temperature of a hot bed to be 50 ℃ and the aperture of the nozzle to be 0.4 mm;

step 3, opening the STL format file in the Cura software, determining the established placing mode of the matrix shape and storing the matrix shape into an SD card; the placing mode is that the rectangular section ABCD of the substrate sheet and X in the three-dimensional coordinate of Cura software₁O₁Y₁Plane coincident and O₁X₁//AB，O₁Y₁// AD, AB and X₁Distance between axes 40mm, AD and Y₁The distance between the shafts is 40 mm;

step 4, inserting the printing wire with the wire diameter of 1.75mm into an extrusion hole of an extruder;

step 5, printing

Printing the base sheet by a three-dimensional printer; the specific process is as follows:

i, setting a printing path; taking a right angle of the substrate sheet as a raw materialPoint O₂Establishing a coordinate system of the substrate sheet, and making the long side of the substrate sheet X₂A shaft whose shorter side of the base sheet is Y₂A shaft; setting a starting point E which is the center of the three-dimensional printer nozzle in the coordinate system (0.2, 29.8);

II, printing a base sheet bottom layer;

printing the bottom layer of the substrate sheet comprises printing a frame of the bottom layer of the substrate sheet and filling printing wires in the frame of the bottom layer;

the thickness of the layer of the frame is 0.125mm, and the wall thickness is 1.2 mm; the filling rate of the printing wires in the frame is 100 percent;

when the bottom layer frame of the base sheet is printed, moving the spray head of the three-dimensional printer to enable the middle point of the spray head to reach the starting point E, and printing the frame of the base sheet according to set printing parameters; the frame is printed for three times to obtain a bottom layer frame of the substrate sheet;

filling printing wires in the bottom layer frame of the obtained substrate sheet;

to this end, the printing of the base sheet bottom layer is completed;

III printing each layer of the base sheet:

repeating the process of printing the bottom layer of the base sheet in the second step, and finishing the printing of each layer by layer; the thickness of each layer is 0.125 mm; printing the base sheet until the base sheet reaches the designed thickness;

iv printing all substrate sheets:

repeating the process of the second step and the process of the third step twice to finish the printing of other substrate sheets;

three substrate sheets are obtained in the step;

second, cutting the carbon fiber cloth

Cutting the carbon fiber cloth into carbon fiber cloth pieces of 60mm multiplied by 30mm according to the design requirement; the number of the carbon fiber cloth pieces is 4 for standby;

step three, preparing a graphene oxide dispersion liquid;

fourthly, preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material:

the specific process is as follows:

step 1, manufacturing a laminated object: the laminated object is formed by stacking a carbon fiber cloth sheet coated with graphene oxide dispersion liquid and a base sheet coated with the graphene oxide dispersion liquid at intervals layer by layer; the bottommost layer and the topmost layer of the laminated object are both carbon fiber cloth;

step 2, placing the obtained laminated object in a pre-heated flat vulcanizing machine, and applying extrusion force through a hydraulic press;

step 3, transferring the extruded laminated material into a vacuum drying oven for final vacuum infiltration treatment to obtain the graphene oxide-carbon fiber hybrid reinforced shape memory composite material;

the vacuum infiltration treatment comprises two processes of vacuum infiltration and vacuum curing.

2. The method for preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material as claimed in claim 1, wherein the Cura software printing parameters set in the step 2 are as follows: the moving speed of the printing nozzle is 50mm/s, the printing temperature is 210 ℃, the temperature of the hot bed is 50 ℃, and the aperture of the nozzle is 0.4 mm.

3. The method according to claim 1, wherein the step 5 of printing the bottom frame of the base sheet comprises printing the dot of the print head along the Y-axis of the coordinate system₂Moving the direction vertically, and printing to the position of (0.2 ); changing the printing direction to make the midpoint of the printing nozzle along X of the coordinate system₂The direction is horizontally moved to (59.8, 0.2); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.8, 29.8); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (0.6, 29.8); finishing the first printing of the frame;

during the second printing of the frame, the printing nozzle is made to start at the position of (0.6,29.8) and along the Y-axis of the coordinate system₂The direction is vertically moved, and printing is carried out to the position of (0.6 ); becomeIn the printing direction, the printing nozzle is made to be along the X of the coordinate system₂The direction is horizontally moved to (59.4, 0.6); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.4, 29.4); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1, 29.4); finishing the second printing of the frame;

during the third printing of the frame, the printing nozzle is made to start at the position (1,29.4) and along the Y-Y of the coordinate system₂Moving the direction vertically, and printing to the position (1, 1); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59, 1); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59, 29); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1.8, 29); and finishing the third printing of the frame to obtain the paired bottom frames of the substrate sheets.

4. The method for preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material according to claim 1, wherein when the printing filament is filled in the bottom layer frame in the step 5 of the first step, the position (1.8,29) is taken as a starting point F of the filling printing filament; moving the printing nozzle to the starting point F, and printing according to set printing parameters; the printing nozzle faces (— X)₂，﹣Y₂) The direction is inclined and moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back, and the direction is inclined to (X)₂，Y₂) The direction is moved to a position 0.2mm away from the inner surface of the upper side of the finished frame and then the frame is turned back again; continue to incline to (-X)₂，﹣Y₂) The direction is diagonally moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back; continue to form a diagonal line (X)₂，Y₂) The direction is moved to a position 0.2mm away from the inner surface of the upper side of the finished frame and then the frame is turned back again; repeating the processes of diagonal movement, turning back, diagonal movement again and turning back again until the printing spray head moves to (58.6, 1.4); thinning the substrate during movement of the print headAnd filling printing wires in the frame of the bottom layer of the film.

5. The method of preparing a graphene oxide-carbon fiber hybrid reinforced shape memory composite of claim 4, wherein the slope of the oblique line is 1.

6. The method for preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material as claimed in claim 1, wherein the third step is a specific process for preparing the graphene oxide dispersion liquid:

step 1, mixing powdered graphene oxide and absolute ethyl alcohol according to a ratio of 1: 5 or 1: 4, mixing to obtain a dark gray black graphene oxide solution;

step 2, transferring the obtained graphene oxide solution to an electromagnetic stirrer, and stirring at a rotating speed of 300rpm for 20min, or at a rotating speed of 400rpm for 15min, or at a rotating speed of 500rpm for 10min to complete the primary dispersion of the graphene oxide in the ethanol solution;

step 3, placing the primarily dispersed graphene oxide solution in an ultrasonic disperser with the frequency of 40kHz and the power of 200W, and dispersing for 30min to realize the final dispersion of the graphene oxide and obtain a prefabricated product of the graphene oxide dispersion solution;

step 4, placing the obtained prefabricated product of the graphene oxide dispersion liquid in a vacuum drying oven for vacuumizing for 6-8 hours to remove gas generated by ethanol volatilization in the dispersion liquid; and obtaining the graphene oxide dispersion liquid.

7. The method for preparing a graphene oxide-carbon fiber hybrid reinforced shape memory composite as claimed in claim 1, wherein the surface of the carbon fiber cloth sheet and the surface of the substrate sheet constituting the laminate in the fourth step are coated with the graphene oxide dispersion liquid.

8. The method according to claim 1, wherein the extrusion temperature is 150 ℃ to 190 ℃, the extrusion pressure is 0.5MPa to 0.9MPa, and the dwell time is 16min to 24min when the extrusion force is applied to the obtained laminate in the fourth step.

9. The method for preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite as claimed in claim 1, wherein, when the extruded laminate is subjected to vacuum infiltration in the fourth step, the vacuum degree of the vacuum infiltration is-0.07 MPa or-0.09 MPa, the temperature is 150 ℃ to 190 ℃, and the vacuum infiltration time is 55min to 75 min; the vacuum degree of the vacuum solidification is-0.07 MPa or-0.09 MPa, the temperature is 50-90 ℃, and the time is 6-10 min.

Background

The shape memory polymer is a novel intelligent high polymer material which can be restored to an original state from a deformed state under the action of external excitation. Shape memory polymers are widely applied to advanced manufacturing fields such as aerospace, weaponry and the like due to the remarkable advantages of low density, large recoverable deformation and the like, but the wide application of the shape memory polymers is greatly limited due to the poor mechanical property of the polymer materials. At present, some researchers combine shape memory polymers with reinforcements with excellent mechanical properties to prepare shape memory composite materials with good mechanical properties such as shape memory function, high strength and high rigidity, and the novel multifunctional composite materials have wide research prospects.

At present, the forming process of the continuous fiber reinforced thermoplastic composite material mainly comprises hot press forming, pultrusion forming, winding forming, Resin Transfer Molding (RTM) and the like. However, the graphene oxide-carbon fiber hybrid reinforced shape memory composite prepared by the above process may have preparation limitations that graphene oxide with a nano structure is easy to agglomerate and difficult to uniformly disperse in the composite, the shape of a workpiece is single, the process is complicated, and the like.

The three-dimensional printing technology, namely the additive manufacturing technology, is an advanced forming process for decomposing a printing model into a plurality of layers of thin slices according to the layer thickness and stacking the thin slices layer by layer to prepare a three-dimensional entity. The forming process is used for forming products with complex geometric shapes, has simple operation process and good product stability, is usually completed under the assistance of a computer, and can be used for printing and forming the shape memory polymer laminated sheet. The application of the three-dimensional printing technology can obviously improve the process level in the manufacturing fields of industrial manufacturing, medical equipment and the like.

The graphene oxide-carbon fiber hybrid reinforced shape memory composite material is high in volume fraction of carbon fibers, small and uneven in gaps between the fibers, possibly mixed with impurity gases, difficult to realize full and uniform impregnation of graphene oxide in the composite material, and capable of effectively discharging the impurity gases in the graphene oxide hybrid reinforced shape memory composite material through impregnation in a vacuum environment, so that a full and uniform impregnation effect is obtained. The three-dimensionally printed shape memory polymer laminated sheet belongs to a hard solid substance at normal temperature and is difficult to adhere to the carbon fiber cloth coated with the graphene peroxide, so that the three-dimensionally printed shape memory polymer laminated sheet is required to be in a viscous state under the condition of heating, and extrusion force is applied to adhere the three-dimensionally printed shape memory polymer laminated sheet and the carbon fiber cloth coated with the graphene peroxide together to form the graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

In the invention creation with the publication number of CN109629076A, aiming at the problem that the common reinforcement does not have the shape memory function or the shape memory polymer has lower mechanical property, the invention provides a preparation method for weaving the shape memory polymer fiber and the continuous fiber and using the mixed fabric as the reinforcement of the composite material, and the method effectively ensures the shape memory and the mechanical property of the reinforcement. However, the method cannot prepare the graphene oxide-carbon fiber hybrid reinforced shape memory composite material, the weaving process of the reinforcement is complex, operators are required to have higher technical level, the production efficiency is low, and the quality stability of the composite material is not easy to guarantee.

The invention patent of publication No. CN109897375B provides a high-strength flexible epoxy resin modified cyanate ester resin/carbon fiber shape memory composite material and a preparation method thereof, the preparation method adopts toughened cyanate ester resin as a matrix, can solve the problems of low mechanical property, low deformation recovery rate and the like of a shape memory polymer in practical application, and has the obvious advantages of simple operation, low cost and the like. However, the invention does not mention the preparation problem of the shape memory composite material reinforced by the mixed nano-scale graphene oxide and the micron-scale carbon fiber, and does not mention the preparation method of the shape memory composite material with a more complex support structure shape by adopting a three-dimensional printing technology, and the composite material capable of being formed has fewer structures and shapes.

Disclosure of Invention

In order to overcome the defects that graphene oxide is not easy to disperse, the composite material generates pores and is layered due to insufficient impregnation or impurity gas inclusion, the size and the shape of the composite material are single and the like in the prior art, the invention provides a preparation method of a graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

The specific process of the invention is as follows.

First, three-dimensionally printing a base sheet:

step 1, establishing a three-dimensional printing matrix shape in Creo software. The shape is a cuboid of 60mm multiplied by 30mm multiplied by 0.5 mm.

And 2, setting Cura software printing parameters.

Printing the base sheet by adopting a layered filling printing method; the base sheet was obtained by layer printing, and the thickness of each layer was 0.125 mm.

The moving speed of the printing nozzle is set to be 50mm/s, the printing temperature is 210 ℃, the temperature of the hot bed is 50 ℃, and the aperture of the nozzle is 0.4 mm.

And 3, opening the STL format file in the Cura software, determining the established placing mode of the matrix shape and storing the matrix shape into the SD card. The placing mode is three-dimensional coordinates of rectangular section ABCD of the substrate sheet and Cura softwareX in (1)₁O₁Y₁Plane coincident and O₁X₁//AB，O₁Y₁// AD, AB and X₁Distance between axes 40mm, AD and Y₁The distance between the axes was 40 mm.

And 4, inserting the printing wire with the wire diameter of 1.75mm into an extrusion hole of an extruder.

Step 5, printing

Printing the base sheet by a three-dimensional printer. The specific process is as follows:

i sets up the printing route. Using a right angle of the substrate sheet as an origin O₂Establishing a coordinate system of the substrate sheet, and making the long side of the substrate sheet X₂A shaft whose shorter side of the base sheet is Y₂A shaft. A starting point E is set in the coordinate system at (0.2,29.8) which is the center of the three-dimensional printer head.

And II, printing a base sheet bottom layer.

And the printing of the substrate thin sheet bottom layer comprises printing a frame of the substrate thin sheet bottom layer and filling printing wires in the frame of the bottom layer.

The thickness of the layer of the frame is 0.125mm, and the wall thickness is 1.2 mm; the filling rate of the printing wires in the frame is 100%.

Printing the bottom frame of the substrate sheet: moving the spray head of the three-dimensional printer to enable the middle point of the spray head to reach the starting point E, and printing the frame of the base sheet according to the set printing parameters; and the frame is printed for three times. Specifically, the midpoint of the printing nozzle is along the Y of the coordinate system₂Moving the direction vertically, and printing to the position of (0.2 ); changing the printing direction to make the midpoint of the printing nozzle along X of the coordinate system₂The direction is horizontally moved to (59.8, 0.2); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.8, 29.8); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally shifted to (0.6, 29.8). And finishing the first printing of the frame.

During the second printing of the frame, the printing nozzle is made to start at the position of (0.6,29.8) and along the Y-axis of the coordinate system₂DirectionVertically moving and printing to the position of (0.6 ); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59.4, 0.6); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.4, 29.4); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction moves horizontally to (1, 29.4). And finishing the second printing of the frame.

During the third printing of the frame, the printing nozzle is made to start at the position (1,29.4) and along the Y-Y of the coordinate system₂Moving the direction vertically, and printing to the position (1, 1); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59, 1); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59, 29); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1.8, 29). And finishing the third printing of the frame.

And finishing printing the bottom layer frame of the base sheet.

Filling printing wires in the bottom layer frame: and (1.8,29) is a starting point F for filling the printing wire. And moving the printing nozzle to the starting point F, and printing according to the set printing parameters. The printing nozzle faces (— X)₂，﹣Y₂) The direction is inclined and moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back, and the direction is inclined to (X)₂，Y₂) The frame is moved to the position 0.2mm away from the inner surface of the upper side of the finished frame in the direction and then is turned back again; continue to incline to (-X)₂，﹣ Y₂) The direction is diagonally moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back; continue to form a diagonal line (X)₂， Y₂) The direction was moved to a distance of 0.2mm from the upper inner surface of the completed frame and folded back again. Repeating the processes of diagonal movement, turning back, diagonal movement again and turning back again until the printing spray head moves to (58.6, 1.4); and filling the printing wires in the bottom layer frame of the substrate sheet in the moving process of the printing spray head.

The slope of the slope is 1. The thickness of the base sheet substrate was 0.125 mm.

To this end, the printing of the base sheet bottom layer is completed.

III printing each layer of the base sheet:

and repeating the process of printing the bottom layer of the base sheet in the second step, and finishing the printing of each layer by layer. The layer thickness of each layer was 0.125 mm. And finishing the printing of the base sheet until the design thickness of the base sheet is reached.

Iv printing all substrate sheets:

and repeating the process of the second step and the process of the third step twice to finish the printing of the rest of the substrate sheets.

Three substrate sheets are obtained in the step.

Step two, cutting the carbon fiber cloth:

cutting the carbon fiber cloth into carbon fiber cloth pieces of 60mm multiplied by 30mm according to the design requirement; the number of the carbon fiber cloth pieces is 4, and the carbon fiber cloth pieces are reserved.

Step three, preparing a graphene oxide dispersion liquid:

the specific process is as follows:

step 1, mixing powdered graphene oxide and absolute ethyl alcohol according to a ratio of 1: 5 or 1: and 4, mixing to obtain a dark gray black graphene oxide solution.

And 2, transferring the obtained graphene oxide solution to an electromagnetic stirrer, and stirring at the rotating speed of 300rpm for 20min, or at the rotating speed of 400rpm for 15min, or at the rotating speed of 500rpm for 10min to finish primary dispersion of the graphene oxide in the ethanol solution.

And 3, placing the primarily dispersed graphene oxide solution in an ultrasonic disperser with the frequency of 40kHz and the power of 200W, and dispersing for 30min to realize the final dispersion of the graphene oxide and obtain a prefabricated product of the graphene oxide dispersion solution.

And 4, placing the obtained prefabricated product of the graphene oxide dispersion liquid in a vacuum drying oven, and vacuumizing for 6-8 hours to remove gas generated by ethanol volatilization in the dispersion liquid. And obtaining the graphene oxide dispersion liquid.

Fourthly, preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material:

the specific process is as follows:

step 1, uniformly coating oxidized graphene dispersion liquid on the front surface and the back surface of each obtained carbon fiber cloth piece; and uniformly coating the front and back surfaces of each obtained substrate sheet with the graphene oxide dispersion liquid.

Stacking the carbon fiber cloth sheet coated with the graphene oxide dispersion liquid and the matrix sheet coated with the graphene oxide dispersion liquid layer by layer at intervals, and enabling the bottommost layer to be the carbon fiber cloth sheet; a substrate sheet is placed on the upper surface of the carbon fiber cloth sheet, and a carbon fiber cloth sheet is placed on the upper surface of the substrate sheet. The circulation is carried out, and a carbon fiber cloth sheet-matrix sheet-carbon fiber cloth sheet-matrix sheet lamination with the bottommost layer and the topmost layer both being carbon fiber cloth is formed.

And 2, placing the obtained laminated object in a pre-heated flat vulcanizing machine, and applying extrusion pressure through a hydraulic press. The extrusion temperature is 150-190 ℃, the extrusion pressure is 0.5-0.9 MPa, and the pressure maintaining time is 16-24 min.

And 3, transferring the extruded laminate into a vacuum drying oven for final vacuum infiltration treatment. The vacuum infiltration treatment comprises two processes of vacuum infiltration and vacuum curing. In the vacuum infiltration process, the vacuum degree is-0.07 MPa or-0.09 MPa, the temperature is 150-190 ℃, and the vacuum infiltration time is 55-75 min. And after the vacuum infiltration process is finished, performing a vacuum curing process. In the vacuum curing process, the vacuum degree is-0.07 MPa or-0.09 MPa, the temperature is 50-90 ℃, and the time is 6-10 min.

And finally, carrying out vacuum infiltration treatment to obtain the graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

The preparation process of the graphene oxide-carbon fiber hybrid reinforced shape memory composite material is shown in fig. 3.

The graphene oxide-carbon fiber hybrid reinforced shape memory composite material is a micro-nano cross-scale hybrid reinforced shape memory composite material prepared by adding nano-scale graphene oxide into a carbon fiber reinforced shape memory composite material. Since the thermal conductivity coefficient of the graphene oxide can reach 3000W/m & lt, the tensile modulus can reach 1.01TPa, and the ultimate strength can reach 116GPa, the thermal response rate and the mechanical bearing capacity of the composite material added with the graphene oxide are improved.

The invention combines the three-dimensional printing technology with the vacuum infiltration and hot press molding technology, can design and manufacture the three-dimensional printing and vacuum infiltration hot press molding composite material pieces with different structural shapes according to the requirements of the structural shapes of the pieces on the basis of ensuring ideal infiltration microstructure of the composite material, effective control of defects and excellent shape memory performance, further realizes the diversification of the structural shapes of the composite material pieces and reduces the manufacturing period of the composite material pieces. The prepared composite material has the shape fixing rate of 97.12 percent, the shape recovery rate of 97.15 percent and excellent shape memory performance. The shape memory matrix is prepared by adopting a three-dimensional printing technology, the problem of the unicity of the shape and the size of the shape memory polymer produced by the traditional process is solved, a product with a complex geometric shape can be formed, and due to the auxiliary action of a computer, the operation process is simple, and the design and manufacturing period is greatly shortened. The preparation process of vacuum infiltration and hot press molding can effectively improve the preparation effect of the composite material. Because the graphene oxide is easy to agglomerate and has poor dispersibility, in order to prevent the graphene oxide from aggregating and precipitating in the composite material, the graphene oxide is dispersed in absolute ethyl alcohol, and the graphene oxide is peeled into a single-layer graphene oxide sheet under the action of electromagnetic stirring and ultrasonic dispersion, so that the graphene oxide is uniformly dispersed. The hot-press forming method adopted by the invention ensures that the first stage of the matrix impregnation in the fiber of the reinforcement is carried out at the extrusion temperature higher than the melting temperature of the matrix, at the moment, the matrix has good fluidity, and simultaneously, under the action of the extrusion force, the matrix can overcome the impregnation resistance to fully impregnate the interior of the composite material, and besides, impurity gas in the composite material can be discharged among fiber layers. The vacuum drying oven is adopted in the vacuum impregnation process, vacuum and high-temperature environments are provided for the second stage of impregnation and solidification of the composite material, the matrix is promoted to have low viscosity and good fluidity, and bubbles generated in the composite material due to ethanol volatilization can be discharged, and the microstructure diagram (figure 6) of the prepared composite material is observed, so that the matrix can be fully impregnated in fiber yarn gaps after being melted, the macro morphology of the composite material can be observed to be good through figure 5, and the air holes, the bubbles and the layering defects of the composite material are effectively controlled. The process system can form the graphene oxide-carbon fiber hybrid reinforced shape memory composite material with excellent shape memory performance.

FIG. 1 is a schematic view of the placement of a substrate to determine its shape.

FIG. 2 is a schematic illustration of a three-dimensional printing substrate sheet printing process.

Fig. 3 is a process flow diagram for preparing a graphene oxide-carbon fiber hybrid reinforced shape memory composite.

FIG. 4 is a schematic view of the alternate placement and stacking of graphene peroxide coated carbon fiber cloth sheets and graphene peroxide coated substrate sheets;

fig. 5 is the graphene oxide-carbon fiber hybrid reinforced shape memory composite of example 1.

Fig. 6 is a microstructure of the graphene oxide-carbon fiber hybrid reinforced shape memory composite mentioned in example 1.

Fig. 7 is a diagram of an implementation of the present invention.

In the figure: 1 is a schematic diagram of a carbon fiber sheet coated with graphene oxide on the surface; 2, a schematic diagram of a substrate sheet coated with graphene oxide on the surface; 3, placing the layers in a laminated manner; 4 is a schematic view of a lamination of the carbon fiber cloth sheet and the matrix sheet; 5 is a graphene oxide-carbon fiber hybrid reinforced shape memory composite material; 6 is the thickness direction of the composite material; and 7, the shape of the graphene oxide-carbon fiber hybrid reinforced shape memory composite material in the thickness direction in the embodiment 1.

Detailed Description

The present invention will be described in detail with reference to examples and comparative examples.

The invention relates to a preparation method of a graphene oxide-carbon fiber hybrid reinforced shape memory composite material, which specifically illustrates the implementation process through 5 embodiments.

The specific process of the invention is as follows:

first, three-dimensionally printing a base sheet:

step 1, establishing a three-dimensional printing matrix shape in Creo software. The shape is a cuboid of 60mm multiplied by 30mm multiplied by 0.5 mm.

And 2, setting Cura software printing parameters.

Printing the base sheet by adopting a layered filling printing method; the base sheet was obtained by layer printing, and the thickness of each layer was 0.125 mm.

The moving speed of the printing nozzle is set to be 50mm/s, the printing temperature is 210 ℃, the temperature of the hot bed is 50 ℃, and the aperture of the nozzle is 0.4 mm.

And 3, opening the STL format file in the Cura software, determining the established placing mode of the matrix shape and storing the matrix shape into the SD card. The placing mode is that the rectangular section ABCD of the substrate sheet and X in the three-dimensional coordinate of Cura software₁O₁Y₁Plane coincident and O₁X₁//AB，O₁Y₁// AD, AB and X₁Distance between axes 40mm, AD and Y₁The distance between the axes was 40 mm.

And 4, inserting the printing wire with the wire diameter of 1.75mm into an extrusion hole of an extruder.

Step 5, printing

Printing the base sheet by a three-dimensional printer. The specific process is as follows:

i sets up the printing route. Using a right angle of the substrate sheet as an origin O₂Establishing a coordinate system of the substrate sheet, and making the long side of the substrate sheet X₂A shaft whose shorter side of the base sheet is Y₂A shaft. A starting point E is set in the coordinate system at (0.2,29.8) which is the center of the three-dimensional printer head.

And II, printing a base sheet bottom layer.

And the printing of the substrate thin sheet bottom layer comprises printing a frame of the substrate thin sheet bottom layer and filling printing wires in the frame of the bottom layer.

The thickness of the layer of the frame is 0.125mm, and the wall thickness is 1.2 mm; the filling rate of the printing wires in the frame is 100%.

Printing the bottom frame of the substrate sheet: moving the spray head of the three-dimensional printer to enable the middle point of the spray head to reach the starting point E, and printing the frame of the base sheet according to the set printing parameters; and the frame is printed for three times. Specifically, the midpoint of the printing nozzle is along the Y of the coordinate system₂Moving the direction vertically, and printing to the position of (0.2 ); changing the printing direction to make the midpoint of the printing nozzle along X of the coordinate system₂The direction is horizontally moved to (59.8, 0.2); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.8, 29.8); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally shifted to (0.6, 29.8). And finishing the first printing of the frame.

During the second printing of the frame, the printing nozzle is made to start at the position of (0.6,29.8) and along the Y-axis of the coordinate system₂The direction is vertically moved, and printing is carried out to the position of (0.6 ); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59.4, 0.6); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.4, 29.4); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction moves horizontally to (1, 29.4). And finishing the second printing of the frame.

During the third printing of the frame, the printing nozzle is made to start at the position (1,29.4) and along the Y-Y of the coordinate system₂Moving the direction vertically, and printing to the position (1, 1); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59, 1); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59, 29); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1.8, 29). And finishing the third printing of the frame.

And finishing printing the bottom layer frame of the base sheet.

Filling printing wires in the bottom layer frame: the position (1.8,29) isFilling the starting point F of the printing wire. And moving the printing nozzle to the starting point F, and printing according to the set printing parameters. The printing nozzle faces (— X)₂，﹣Y₂) The direction is inclined and moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back, and the direction is inclined to (X)₂，Y₂) The frame is moved to the position 0.2mm away from the inner surface of the upper side of the finished frame in the direction and then is turned back again; continue to incline to (-X)₂，﹣ Y₂) The direction is diagonally moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back; continue to form a diagonal line (X)₂， Y₂) The direction was moved to a distance of 0.2mm from the upper inner surface of the completed frame and folded back again. Repeating the processes of diagonal movement, turning back, diagonal movement again and turning back again until the printing spray head moves to (58.6, 1.4); and filling the printing wires in the bottom layer frame of the substrate sheet in the moving process of the printing spray head.

The slope of the slope is 1. The thickness of the base sheet substrate was 0.125 mm.

To this end, the printing of the base sheet bottom layer is completed.

III printing each layer of the base sheet:

and repeating the process of printing the bottom layer of the base sheet in the second step, and finishing the printing of each layer by layer. The layer thickness of each layer was 0.125 mm. And finishing the printing of the base sheet until the design thickness of the base sheet is reached.

Iv printing all substrate sheets:

and repeating the process of the second step and the process of the third step twice to finish the printing of the rest of the substrate sheets.

Three substrate sheets are obtained in the step.

Step two, cutting the carbon fiber cloth:

cutting the carbon fiber cloth into carbon fiber cloth pieces of 60mm multiplied by 30mm according to the design requirement; the number of the carbon fiber cloth pieces is 4, and the carbon fiber cloth pieces are reserved.

Step three, preparing a graphene oxide dispersion liquid:

the specific process is as follows:

step 1, mixing powdered graphene oxide and absolute ethyl alcohol according to a ratio of 1: 5 or 1: and 4, mixing to obtain a dark gray black graphene oxide solution.

And 2, transferring the obtained graphene oxide solution to an electromagnetic stirrer, and stirring at the rotating speed of 300rpm for 20min, or at the rotating speed of 400rpm for 15min, or at the rotating speed of 500rpm for 10min to finish primary dispersion of the graphene oxide in the ethanol solution.

And 3, placing the primarily dispersed graphene oxide solution in an ultrasonic disperser with the frequency of 40kHz and the power of 200W, and dispersing for 30min to realize the final dispersion of the graphene oxide and obtain a prefabricated product of the graphene oxide dispersion solution.

And 4, placing the obtained prefabricated product of the graphene oxide dispersion liquid in a vacuum drying oven, and vacuumizing for 6-8 h to remove gas generated by ethanol volatilization in the dispersion liquid. And obtaining the graphene oxide dispersion liquid.

Fourthly, preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material:

the specific process is as follows:

step 1, uniformly coating oxidized graphene dispersion liquid on the front surface and the back surface of each obtained carbon fiber cloth piece; and uniformly coating the front and back surfaces of each obtained substrate sheet with the graphene oxide dispersion liquid.

Stacking the carbon fiber cloth sheet coated with the graphene oxide dispersion liquid and the matrix sheet coated with the graphene oxide dispersion liquid layer by layer at intervals, and enabling the bottommost layer to be the carbon fiber cloth sheet; a substrate sheet is placed on the upper surface of the carbon fiber cloth sheet, and a carbon fiber cloth sheet is placed on the upper surface of the substrate sheet. The circulation is carried out, and a carbon fiber cloth sheet-matrix sheet-carbon fiber cloth sheet-matrix sheet lamination with the bottommost layer and the topmost layer both being carbon fiber cloth is formed.

And 2, placing the obtained laminated object in a pre-heated flat vulcanizing machine, and applying extrusion pressure through a hydraulic press. The extrusion temperature is 150-190 ℃, the extrusion pressure is 0.5-0.9 MPa, and the pressure maintaining time is 16-24 min.

And 3, transferring the laminated product to a vacuum drying oven for final vacuum infiltration treatment. The vacuum infiltration treatment comprises two processes of vacuum infiltration and vacuum solidification. In the vacuum infiltration process, the vacuum degree is-0.07 MPa or-0.09 MPa, the temperature is 150-190 ℃, and the vacuum infiltration time is 55-75 min. And after the vacuum infiltration process is finished, performing a vacuum curing process. In the vacuum curing process, the vacuum degree is-0.07 MPa or-0.09 MPa, the temperature is 50-90 ℃, and the time is 6-10 min.

And finally, carrying out vacuum infiltration treatment to obtain the graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

The process parameters for each example of the present invention are shown in table 1.

TABLE 1

In order to verify the effect of the present invention, the graphene oxide-carbon fiber hybrid reinforced shape memory composite material prepared in each example was measured, and the results thereof are shown in table 2.

TABLE 2

Comparative example 1

The comparative example is a specific process for preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material by adopting a three-dimensional printing, vacuum infiltration and hot-pressing curing method in the prior art:

first, three-dimensionally printing a base sheet:

step 1, establishing a three-dimensional printing matrix shape in Creo software. The shape is a cuboid of 60mm multiplied by 30mm multiplied by 0.5 mm.

And 2, setting Cura software printing parameters.

Printing the base sheet by adopting a layered filling printing method; the base sheet was obtained by layer printing, and the thickness of each layer was 0.125 mm.

The moving speed of the printing nozzle is set to be 50mm/s, the printing temperature is 210 ℃, the temperature of the hot bed is 50 ℃, and the aperture of the nozzle is 0.4 mm.

And 3, opening the STL format file in the Cura software, determining the established placing mode of the matrix shape and storing the matrix shape into the SD card. The placing mode is that the rectangular section ABCD of the substrate sheet and X in the three-dimensional coordinate of Cura software₁O₁Y₁Plane coincident and O₁X₁//AB，O₁Y₁// AD, AB and X₁Distance between axes 40mm, AD and Y₁The distance between the axes was 40 mm.

And 4, inserting the printing wire with the wire diameter of 1.75mm into an extrusion hole of an extruder.

Step 5, printing

Printing the base sheet by a three-dimensional printer. The specific process is as follows:

i sets up the printing route. Using a right angle of the substrate sheet as an origin O₂Establishing a coordinate system of the substrate sheet, and making the long side of the substrate sheet X₂A shaft whose shorter side of the base sheet is Y₂A shaft. A starting point E is set in the coordinate system at (0.2,29.8) which is the center of the three-dimensional printer head.

And II, printing a base sheet bottom layer.

And the printing of the substrate thin sheet bottom layer comprises printing a frame of the substrate thin sheet bottom layer and filling printing wires in the frame of the bottom layer.

The thickness of the layer of the frame is 0.125mm, and the wall thickness is 1.2 mm; the filling rate of the printing wires in the frame is 100%.

Printing the bottom frame of the substrate sheet: moving the spray head of the three-dimensional printer to enable the middle point of the spray head to reach the starting point E, and printing the frame of the base sheet according to the set printing parameters; and the frame is printed for three times. Specifically, the midpoint of the printing nozzle is along the Y of the coordinate system₂Moving the direction vertically, and printing to the position of (0.2 ); changing the printing direction to make the midpoint of the printing nozzle along X of the coordinate system₂The direction is horizontally moved to (59.8, 0.2); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂Direction of vertical movementTo (59.8, 29.8); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally shifted to (0.6, 29.8). And finishing the first printing of the frame.

During the second printing of the frame, the printing nozzle is made to start at the position of (0.6,29.8) and along the Y-axis of the coordinate system₂The direction is vertically moved, and printing is carried out to the position of (0.6 ); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59.4, 0.6); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.4, 29.4); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction moves horizontally to (1, 29.4). And finishing the second printing of the frame.

During the third printing of the frame, the printing nozzle is made to start at the position (1,29.4) and along the Y-Y of the coordinate system₂Moving the direction vertically, and printing to the position (1, 1); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59, 1); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59, 29); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1.8, 29). And finishing the third printing of the frame.

And finishing printing the bottom layer frame of the base sheet.

Filling printing wires in the bottom layer frame: and (1.8,29) is a starting point F for filling the printing wire. And moving the printing nozzle to the starting point F, and printing according to the set printing parameters. The printing nozzle faces (— X)₂，﹣Y₂) The direction is inclined and moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back, and the direction is inclined to (X)₂，Y₂) The frame is moved to the position 0.2mm away from the inner surface of the upper side of the finished frame in the direction and then is turned back again; continue to incline to (-X)₂，﹣ Y₂) The direction is diagonally moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back; continue to form a diagonal line (X)₂， Y₂) The direction movement being performed to a distanceThe upper inner surface of the frame is folded back again at the position of 0.2 mm. Repeating the processes of diagonal movement, turning back, diagonal movement again and turning back again until the printing spray head moves to (58.6, 1.4); and filling the printing wires in the bottom layer frame of the substrate sheet in the moving process of the printing spray head.

The slope of the slope is 1. The thickness of the base sheet substrate was 0.125 mm.

To this end, the printing of the base sheet bottom layer is completed.

III printing each layer of the base sheet:

and repeating the process of printing the bottom layer of the base sheet in the second step, and finishing the printing of each layer by layer. The layer thickness of each layer was 0.125 mm. And finishing the printing of the base sheet until the design thickness of the base sheet is reached.

Iv printing all substrate sheets:

and repeating the process of the second step and the process of the third step twice to finish the printing of the rest of the substrate sheets.

Three substrate sheets are obtained in the step.

Step two, cutting the carbon fiber cloth:

cutting the T300 bidirectional carbon fiber cloth into carbon fiber cloth pieces of 60mm multiplied by 30mm according to design requirements; the number of the carbon fiber cloth pieces is 4, and the carbon fiber cloth pieces are reserved.

Step three, preparing a graphene oxide dispersion liquid:

the specific process is as follows:

step 1, mixing powdered graphene oxide and absolute ethyl alcohol according to a ratio of 1: 5 to obtain dark gray black graphene oxide solution.

And 2, transferring the obtained graphene oxide solution to an electromagnetic stirrer, and stirring at the rotating speed of 300rpm for 20min to finish the primary dispersion of the graphene oxide in the ethanol solution.

And 3, placing the primarily dispersed graphene oxide solution in an ultrasonic disperser with the frequency of 40kHz and the power of 200W, and dispersing for 30min to realize the final dispersion of the graphene oxide, thereby obtaining the graphene oxide dispersion liquid.

Fourthly, preparing the graphene oxide-T300 carbon fiber hybrid reinforced shape memory composite material:

the specific process is as follows:

step 1, uniformly coating oxidized graphene dispersion liquid on the front surface and the back surface of each obtained carbon fiber cloth piece; and uniformly coating the front and back surfaces of each obtained substrate sheet with the graphene oxide dispersion liquid.

Stacking the carbon fiber cloth sheet coated with the graphene oxide dispersion liquid and the matrix sheet coated with the graphene oxide dispersion liquid layer by layer at intervals, and enabling the bottommost layer to be the carbon fiber cloth sheet; a substrate sheet is placed on the upper surface of the carbon fiber cloth sheet, and a carbon fiber cloth sheet is placed on the upper surface of the substrate sheet. The circulation is carried out, and a carbon fiber cloth sheet-matrix sheet-carbon fiber cloth sheet-matrix sheet lamination with the bottommost layer and the topmost layer both being carbon fiber cloth is formed.

And 2, placing the obtained laminated object in a flat vulcanizing machine preheated to 170 ℃ in advance, and applying extrusion force through a hydraulic press. The extrusion temperature is 170 ℃, the extrusion pressure is 0.7MPa, and the pressure maintaining time is 20 min.

And 3, transferring the laminated product to a vacuum drying oven for final vacuum infiltration treatment. The vacuum infiltration treatment comprises two processes of vacuum infiltration and vacuum solidification. In the vacuum infiltration process, the vacuum degree is-0.09 MPa, the temperature is 180 ℃, and the vacuum infiltration time is 60 min. And after the vacuum infiltration process is finished, performing a vacuum curing process. In the vacuum curing process, the vacuum degree is-0.09 MPa, the temperature is 50 ℃, and the time is 10 min.

And finally, carrying out vacuum infiltration treatment to obtain the graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

The carbon fiber reinforced shape memory composite material prepared in the comparative example had a shape fixation rate of 94.13% and a shape recovery rate of 93.27%.

Comparative example 2

The comparative example is a specific process for preparing the carbon fiber reinforced shape memory composite material by adopting a three-dimensional printing and vacuum infiltration and hot-pressing curing method in the prior art:

first, three-dimensionally printing a base sheet:

step 1, establishing a three-dimensional printing matrix shape in Creo software. The shape is a cuboid of 60mm multiplied by 30mm multiplied by 0.5 mm.

And 2, setting Cura software printing parameters.

Printing the base sheet by adopting a layered filling printing method; the base sheet was obtained by layer printing, and the thickness of each layer was 0.125 mm.

The moving speed of the printing nozzle is set to be 50mm/s, the printing temperature is 210 ℃, the temperature of the hot bed is 50 ℃, and the aperture of the nozzle is 0.4 mm.

And 3, opening the STL format file in the Cura software, determining the established placing mode of the matrix shape and storing the matrix shape into the SD card. The placing mode is that the rectangular section ABCD of the substrate sheet and X in the three-dimensional coordinate of Cura software₁O₁Y₁Plane coincident and O₁X₁//AB，O₁Y₁// AD, AB and X₁Distance between axes 40mm, AD and Y₁The distance between the axes was 40 mm.

And 4, inserting the printing wire with the wire diameter of 1.75mm into an extrusion hole of an extruder.

Step 5, printing

Printing the base sheet by a three-dimensional printer. The specific process is as follows:

i sets up the printing route. Using a right angle of the substrate sheet as an origin O₂Establishing a coordinate system of the substrate sheet, and making the long side of the substrate sheet X₂A shaft whose shorter side of the base sheet is Y₂A shaft. A starting point E is set in the coordinate system at (0.2,29.8) which is the center of the three-dimensional printer head.

And II, printing a base sheet bottom layer.

And the printing of the substrate thin sheet bottom layer comprises printing a frame of the substrate thin sheet bottom layer and filling printing wires in the frame of the bottom layer.

The thickness of the layer of the frame is 0.125mm, and the wall thickness is 1.2 mm; the filling rate of the printing wires in the frame is 100%.

Printing the substrateBody thin sheet bottom layer frame: moving the spray head of the three-dimensional printer to enable the middle point of the spray head to reach the starting point E, and printing the frame of the base sheet according to the set printing parameters; and the frame is printed for three times. Specifically, the midpoint of the printing nozzle is along the Y of the coordinate system₂Moving the direction vertically, and printing to the position of (0.2 ); changing the printing direction to make the midpoint of the printing nozzle along X of the coordinate system₂The direction is horizontally moved to (59.8, 0.2); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.8, 29.8); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally shifted to (0.6, 29.8). And finishing the first printing of the frame.

During the second printing of the frame, the printing nozzle is made to start at the position of (0.6,29.8) and along the Y-axis of the coordinate system₂The direction is vertically moved, and printing is carried out to the position of (0.6 ); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59.4, 0.6); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59.4, 29.4); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction moves horizontally to (1, 29.4). And finishing the second printing of the frame.

During the third printing of the frame, the printing nozzle is made to start at the position (1,29.4) and along the Y-Y of the coordinate system₂Moving the direction vertically, and printing to the position (1, 1); changing the printing direction to make the printing nozzle along the X of the coordinate system₂The direction is horizontally moved to (59, 1); changing the printing direction to make the printing nozzle along the Y of the coordinate system₂The direction is vertically moved to (59, 29); changing the printing direction to make the printing nozzle along the-X of the coordinate system₂The direction is horizontally moved to (1.8, 29). And finishing the third printing of the frame.

And finishing printing the bottom layer frame of the base sheet.

Filling printing wires in the bottom layer frame: and (1.8,29) is a starting point F for filling the printing wire. Moving the print head to the starting point FAnd printing is carried out according to the set printing parameters. The printing nozzle faces (— X)₂，﹣Y₂) The direction is inclined and moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back, and the direction is inclined to (X)₂，Y₂) The frame is moved to the position 0.2mm away from the inner surface of the upper side of the finished frame in the direction and then is turned back again; continue to incline to (-X)₂，﹣ Y₂) The direction is diagonally moved to a position which is 0.2mm away from the inner surface of the left side of the finished frame and is folded back; continue to form a diagonal line (X)₂，Y₂) The direction was moved to a distance of 0.2mm from the upper inner surface of the completed frame and folded back again. Repeating the processes of diagonal movement, turning back, diagonal movement again and turning back again until the printing spray head moves to (58.6, 1.4); and filling the printing wires in the bottom layer frame of the substrate sheet in the moving process of the printing spray head.

The slope of the slope is 1. The thickness of the base sheet substrate was 0.125 mm.

To this end, the printing of the base sheet bottom layer is completed.

III printing each layer of the base sheet:

and repeating the process of printing the bottom layer of the base sheet in the second step, and finishing the printing of each layer by layer. The layer thickness of each layer was 0.125 mm. And finishing the printing of the base sheet until the design thickness of the base sheet is reached.

Iv printing all substrate sheets:

and repeating the process of the second step and the process of the third step twice to finish the printing of the rest of the substrate sheets.

Three substrate sheets are obtained in the step.

Secondly, cutting the T300 carbon fiber cloth:

cutting the T300 carbon fiber cloth into carbon fiber cloth pieces of 60mm multiplied by 30mm according to design requirements; the number of the carbon fiber cloth pieces is 4, and the carbon fiber cloth pieces are reserved.

Step three, preparing a graphene oxide dispersion liquid:

the specific process is as follows:

step 1, mixing powdered graphene oxide and absolute ethyl alcohol according to a ratio of 1: 5 to obtain dark gray black graphene oxide solution.

And 2, transferring the obtained graphene oxide solution to an electromagnetic stirrer, and stirring at the rotating speed of 300rpm for 20min to finish the primary dispersion of the graphene oxide in the ethanol solution.

And 3, placing the primarily dispersed graphene oxide solution in an ultrasonic disperser with the frequency of 40kHz and the power of 200W, and dispersing for 30min to realize the final dispersion of the graphene oxide and obtain a prefabricated product of the graphene oxide dispersion solution.

And 4, placing the obtained prefabricated product of the graphene oxide dispersion liquid in a vacuum drying oven for vacuumizing for 8 hours to remove gas generated by volatilization of ethanol in the dispersion liquid. And obtaining the graphene oxide dispersion liquid.

Fourthly, preparing the graphene oxide-carbon fiber hybrid reinforced shape memory composite material:

the specific process is as follows:

step 1, uniformly coating oxidized graphene dispersion liquid on the front surface and the back surface of each obtained carbon fiber cloth piece; and uniformly coating the front and back surfaces of each obtained substrate sheet with the graphene oxide dispersion liquid.

Stacking the carbon fiber cloth sheet coated with the graphene oxide dispersion liquid and the matrix sheet coated with the graphene oxide dispersion liquid layer by layer at intervals, and enabling the bottommost layer to be the carbon fiber cloth sheet; a substrate sheet is placed on the upper surface of the carbon fiber cloth sheet, and a carbon fiber cloth sheet is placed on the upper surface of the substrate sheet. The circulation is carried out, and a carbon fiber cloth sheet-matrix sheet-carbon fiber cloth sheet-matrix sheet lamination with the bottommost layer and the topmost layer both being carbon fiber cloth is formed.

And 2, placing the obtained laminated object in a flat vulcanizing machine preheated to 170 ℃ in advance, and applying extrusion force through a hydraulic press. The extrusion temperature is 170 ℃, the extrusion pressure is 0.7MPa, and the pressure maintaining time is 20 min.

And 3, transferring the laminated object to a vacuum drying oven to carry out a vacuum curing process. In the vacuum curing process, the vacuum degree is-0.09 MPa, the temperature is 50 ℃, and the time is 10 min.

And finally, carrying out vacuum infiltration treatment to obtain the graphene oxide-carbon fiber hybrid reinforced shape memory composite material.

The shape fixation rate of the carbon fiber reinforced shape memory composite material prepared in the comparative example was 93.89%, and the shape recovery rate was 93.74%.

The graphene oxide-carbon fiber hybrid reinforced shape memory composite material prepared in embodiment 1 of the invention has a shape fixation rate of 97.12% and a shape recovery rate of 97.15%; the graphene oxide-carbon fiber hybrid reinforced shape memory composite prepared in example 2 had a shape fixation rate of 96.53% and a shape recovery rate of 96.71%; the graphene oxide-carbon fiber hybrid reinforced shape memory composite prepared in example 3 had a shape fixation rate of 96.32% and a shape recovery rate of 96.67%; the graphene oxide-carbon fiber hybrid reinforced shape memory composite prepared in example 4 had a shape fixation rate of 95.34% and a shape recovery rate of 96.79%; the graphene oxide-carbon fiber hybrid reinforced shape memory composite prepared in example 5 had a shape fixation rate of 95.14% and a shape recovery rate of 96.27%; in contrast, in comparative example 1, the graphene oxide-carbon fiber hybrid reinforced shape memory composite material in which the graphene oxide dispersion liquid was not subjected to vacuum treatment had a shape fixation rate of 94.13% and a shape recovery rate of 93.27%; the graphene oxide-carbon fiber hybrid reinforced shape memory composite of comparative example 2, in which the composite was not subjected to the vacuum impregnation process, had a shape fixation rate of 93.89% and a shape recovery rate of 93.74%.

When the graphene oxide dispersion liquid is not subjected to vacuum pumping treatment, more ethanol solution residues in the dispersion liquid can be caused, the ethanol solution volatilizes to generate bubbles in the process of carrying out hot press molding and vacuum infiltration on the composite material, the bubbles form initial defects in the composite material, and the defects can gradually expand into cracks or delamination when the composite material is subjected to a shape memory test, so that the composite material is caused to lose efficacy, and the shape memory performance of the composite material is seriously hindered.

When the composite material is not subjected to the vacuum infiltration process, insufficient matrix infiltration can occur in the composite material, resulting in matrix aggregation in some regions and matrix deficiency in some regions, and in these matrix-poor regions, fibers that are not attached to the matrix can fail to fail during the shape memory performance test, thereby reducing the shape memory capacity of the composite material.

TABLE 3