1. A preparation method of ceramic fiber for high temperature test comprises the following steps:

s1: degumming the ceramic bundling fiber;

s2: drawing monofilaments from the ceramic bundling fibers to form ceramic single fibers;

s3: manufacturing a hollow tool frame by adopting a first high-temperature-resistant material, and arranging a suspension rod made of a second high-temperature-resistant material in the frame;

s4: one end of the ceramic monofilament fiber is fixed on the suspension rod, and the suspended ceramic monofilament fiber is in a vertical suspension state;

s5: the work suspended with the ceramic monofilament fiber is arranged in a heating device at the temperature of 1000-1500 ℃ for heating for 0.8-1.2 hours.

2. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the first high temperature resistant material is polycrystalline mullite fiber.

3. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the second high temperature resistant material is alumina.

4. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the ceramic monofilament fiber is fixedly connected with the suspension rod through high-temperature glue.

5. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the heating temperature of the tube furnace is 1200 ℃.

6. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the heating time of the tube furnace is one hour.

7. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the degumming method of the ceramic monofilament fiber is a hot air degradation method in GB/T34520.1-2017.

8. The method for preparing ceramic fiber for high temperature test according to claim 1, wherein: the heating device is a tube furnace.

Background

The ceramic fiber (SiCF) reinforced ceramic matrix composite has excellent high-temperature mechanical properties, so that the SiCF is widely used as a high-temperature structural component, such as a rocket tube, a missile nose cone, a wing leading edge, a brake pad and the like, and the SiCF is used as a novel semiconductor material and becomes the most important semiconductor material for manufacturing short-wavelength optical electronic devices, high-temperature devices, anti-irradiation devices and high-power and high-frequency electronic devices by virtue of excellent physicochemical characteristics and electrical characteristics of the SiCF. The SiCF material has huge application potential in the aspects of high temperature, high frequency, high power, high voltage photoelectron, radiation resistance and the like.

The high-temperature retention rate of the continuous silicon carbide monofilament fiber under the air atmosphere is not specified in national standards at present, only GB/T34520.7-2017 is consulted, and the inert atmosphere is changed into the air atmosphere in the sample treatment process, but the method has the following problems: the high temperature strength retention in air atmosphere did not meet the expected requirements.

The analysis reason is that continuous silicon carbide fiber bundles are adhered at high temperature under the air atmosphere, ceramic single fibers are adhered together, the operation is carried out according to GB/T34520.5-2017.7, the fiber is damaged in the fiber drawing process after the temperature is reduced, the strength is reduced, and the retention rate of high-temperature strength is reduced.

Disclosure of Invention

Therefore, aiming at the problems, the invention provides the preparation method of the ceramic fiber for the high-temperature test, which has the advantages of simple structure, low production cost and accurate test.

In order to realize the technical problem, the solution scheme adopted by the invention is as follows: a preparation method of ceramic fiber for high temperature test comprises the following steps:

s1: degumming the ceramic bundling fiber by a hot air method;

s2: drawing monofilaments from the ceramic bundling fibers to form ceramic single fibers;

s3: manufacturing a hollow tool frame by adopting a first high-temperature-resistant material, and arranging a suspension rod made of a second high-temperature-resistant material in the frame;

s4: one end of the ceramic monofilament fiber is fixed on the suspension rod, and the suspended ceramic monofilament fiber is in a vertical suspension state;

s5: the work suspended with the ceramic monofilament fiber is arranged in a heating device at the temperature of 1000-1500 ℃ for heating for 0.8-1.2 hours.

The further improvement is that: the first high temperature resistant material is polycrystalline mullite fiber.

The further improvement is that: the second high temperature resistant material is alumina.

The further improvement is that: the ceramic monofilament fiber is fixedly connected with the suspension rod through high-temperature glue.

The further improvement is that: the heating temperature of the tube furnace is 1200 ℃.

The further improvement is that: the heating time of the tube furnace is one hour.

The further improvement is that: the degumming method of the ceramic monofilament fiber is a hot air degradation method in GB/T34520.1-2017.

The further improvement is that: the heating device is a tube furnace.

By adopting the technical scheme, the invention has the beneficial effects that: 1. substances which are not beneficial to testing can not be introduced in the experiment, the service life of the instrument is more beneficial, and the operation mode is simpler and more convenient. 2. The test data shows that the high-temperature retention rate of the ceramic monofilament fiber is higher than that of the ceramic monofilament fiber by a reference national standard method, the dispersion coefficient is smaller, and the display data is more accurate. 3. The suspension rod is made of alumina, is high temperature resistant and stable, and does not generate substances influencing the experiment; 4. the frame is made of polycrystalline mullite fiber, has light weight, avoids damaging the tube furnace, has strong plasticity, is convenient to process, is suitable for tube furnaces with various specifications, has stable material quality, and can not release substances which influence the experiment.

Drawings

FIG. 1 is a schematic structural diagram of a frame and a suspension rod according to an embodiment of the present invention.

FIG. 2 is a schematic top view of the frame and suspension rods according to the embodiment of the present invention.

Detailed Description

The invention will now be further described with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 2, disclosed in an embodiment of the present invention is a method for preparing a ceramic fiber for a high temperature test, including the steps of:

s1: degumming the ceramic bundling fibers by adopting a hot air method in GB/T34520.1-2017;

s2: drawing monofilaments from the ceramic bundling fibers to form ceramic single fibers;

s3: according to the size of a heating space of the tube furnace, a frame 1 of the hollow tool is made of polycrystalline mullite fiber, and a suspension rod 2 made of alumina is arranged in the frame 1;

s4: coating high-temperature glue on the suspension rod 2, clamping one end of the ceramic single fiber degummed according to 7.2 in GB/T34520.1-2017 by using a pair of tweezers, vertically sticking the ceramic single fiber on the suspension rod 2, and enabling the suspended ceramic single fiber to be in a vertically suspended state;

s5: the work with the suspended ceramic monofilament fibers was placed in a tube furnace at 1200 c for one hour of heating.

The following results are shown in a comparison table (table 1) by respectively performing a high-temperature strength retention rate test on the same ceramic fiber by adopting a treatment method (changing inert atmosphere into air atmosphere) of placing a bundle filament in a ceramic boat for high-temperature filament drying and then drawing the filament by using a reference national standard GB/T34520.7-2017:

TABLE 1

The retention rate of the high-temperature strength of the oxygen atmosphere is improved from 61.69% to 85.52%, and the test data show that the test strength of the same ceramic fiber is obviously lower than that of the ceramic fiber obtained by the method (baking at 1200 ℃ for 1h in the air atmosphere) of the patent application under the treatment condition that the ceramic boat is placed in a bundled wire (baking at 1200 ℃ for 1h in the air atmosphere), so that the ceramic fiber is damaged because the ceramic fiber is placed in the ceramic boat and then is drawn out after the ceramic boat is baked.

In the experiment, because the tube furnace tube has limited bearing, the frame 1 is made of polycrystalline mullite fiber, the material can be cut according to the required size on site, the material has light weight, and a light mold is selected to protect the instrument.

Considering that the two ends of the ceramic single fiber are stuck to the upper and lower parallel suspension rods to cause thermal expansion and cold contraction, the ceramic single fiber is damaged, and finally, the mode that the suspension rod 2 is embedded at the top end is adopted.

The alumina and the polycrystalline mullite fiber can not release substances which influence the experiment at high temperature.

Based on the scheme, the degumming method can also be a thermal degradation method or a solvent removal method. The heating temperature in the heating device can be 1000 ℃ for 1.2 hours in time; or 1500 ℃ for 0.8 hour.

The first refractory material may also be a quartz tube.

The second refractory material may also be a high temperature refractory brick.

Modifications and variations of the present invention are within the scope of the claims and are not limited by the disclosure of the embodiments.