Efficient preparation process of short fiber hard thermal insulation composite material

Abstract

The invention provides a high-efficiency preparation process of a short-fiber hard thermal-insulation composite material. The high-efficiency preparation process comprises the following steps: immersing carbon fibers of which the raw material is short fibers into a modifier for surface treatment, and then sequentially carrying out metal modification, carbon layer deposition and inorganic matter layer coating on the surface, carbon fibers and inorganic materials are subjected to composite hot pressing, then high-temperature graphitization treatment is carried out, and the short fiber hard heat preservation composite material is obtained. According to the process, the connection strength between the short fibers and the inorganic material can be improved, the mechanical performance of the composite material is improved, the graphitization degree is higher, and the good heat preservation performance is achieved.

Description

Technical Field

[0001] The invention relates to the field of rigid thermal insulation materials, in particular to an efficient preparation process of a short-fiber rigid thermal insulation composite material. Background Art

[0002] With the development of science and technology, the role of materials in various fields has become more and more prominent, and the discovery and preparation of new materials has become more and more important. However, the discovery of new materials is limited by various conditions such as opportunities. Therefore, using existing materials to prepare new materials by changing or adjusting the preparation process has become an important demand for materials. The large thermal expansion and contraction of ceramic materials will reduce the structural stability and safety reliability of heat-resistant components, weaken or even destroy the heat-resistant and anti-oxidation ablation capabilities of the materials. Carbon fiber is a new type of fiber material with high strength and high modulus fiber. After carbon fiber and ceramic materials are compounded, the internal stress generated by high-temperature expansion in the material can be reduced, and the thermal shock resistance of the material can be increased. The hard thermal insulation material prepared in this way can be widely used in high-temperature operations. Summary of the invention

[0003] The present invention provides an efficient preparation process of a short fiber rigid thermal insulation composite material: the carbon fiber whose raw material is short fiber is immersed in a modifier for surface treatment, and then metal modification, carbon layer deposition and inorganic layer coating are sequentially performed on the surface; the carbon fiber and inorganic material are compositely hot pressed, and then high-temperature graphitization treatment is performed to obtain the short fiber rigid thermal insulation composite material. This process can improve the connection strength between the short fiber and the inorganic material, improve the mechanical properties of the composite material, and the graphitization degree is higher and has good thermal insulation performance.

[0004] An efficient preparation process for a short fiber rigid thermal insulation composite material, characterized in that the method comprises:

[0005] 1) taking chopped carbon fibers, dispersing them in a mixed solution of acetone and tetrahydrofuran, washing, and drying to obtain pretreated carbon fibers;

[0006] 2) The pretreated carbon fiber and titanium metal nanopowder are mixed evenly, and then placed in a tube furnace, heated to 1000-1200° C. under a protective atmosphere for calcination; cooled to 550-650° C., acetylene gas is introduced, kept warm for a predetermined time, cooled to room temperature and taken out;

[0007] 3) soaking the product of step 2 in a zirconium salt solution, taking it out and drying it, then placing it in a tube furnace, heating it to 550-650° C. under a protective atmosphere, calcining it, cooling it to room temperature, taking it out and crushing it to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer;

[0008] 4) Dispersing zirconium oxide powder, silicon carbide powder, carbon fiber obtained in step 3, phenolic resin and silane coupling agent in ethanol, drying, and hot pressing to shape; placing the shaped embryo body in a tubular furnace, heating to 1200-2200° C. for calcination under a protective atmosphere, and then cooling to 500-600° C. for annealing to obtain a short fiber hard thermal insulation composite material.

[0009] Furthermore, in step 1, the diameter of the chopped carbon fiber is 5-8 μm and the length is 1-2 mm; the mass ratio of acetone to tetrahydrofuran is 1:1-1.5.

[0010] Furthermore, in step 2, the pretreated carbon fiber and the titanium metal powder are mixed in a mass ratio of 100:10-15, and the particle size of the titanium metal powder is 500-1000 nm.

[0011] Furthermore, in step 2, the high temperature calcination temperature is 1000-1200° C. for 4-6 hours in a tubular furnace under nitrogen protection; then the temperature is lowered to 550-650° C., acetylene gas is introduced at a flow rate of 100-150 ml / min, and the temperature is kept for 0.5-3 hours.

[0012] Furthermore, in step 3, the concentration of the zirconium nitrate solution is 8-12wt%, and the immersion time is 3-6h.

[0013] Furthermore, in step 3, the calcination temperature in the tubular furnace under nitrogen protection is 550-650° C., and the calcination time is 4-6 hours.

[0014] Furthermore, in the step 4, zirconium oxide powder with an average particle size of 30-50 microns, silicon carbide powder with an average particle size of 30-50 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 are mixed and dispersed in ethanol in a mass ratio of 80-100:80-100:30-60:15-20:3-5, and the solid content is adjusted to 40-60wt%.

[0015] Furthermore, in step 4, the hot pressing temperature is 80-90° C., the hot pressing time is 10-30 min, and the hot pressing pressure is 30-35 MPa.

[0016] Furthermore, in step 4, the shaped embryo body is placed in a tubular furnace, heated to 1200-1400° C. and calcined for 6-8 hours under nitrogen protection, then heated to 1800-2200° C. and calcined for 1-2 hours, and then cooled to 500-600° C. and annealed for 0.5-1 hour to obtain a short fiber rigid thermal insulation composite material.

[0017] A short fiber hard thermal insulation composite material, the material is prepared by adopting the process.

[0018] Beneficial technical effects of the present invention

[0019] 1) The carbon fiber is modified with titanium metal. The metal can act as a catalyst to promote the deposition of carbon on the surface of the carbon fiber during the carbon deposition process, thereby improving the deposition effect and partially forming titanium carbide hard alloy to improve the strength of the carbon fiber;

[0020] 2) The carbon layer deposited on the surface of the carbon fiber has a high specific surface area due to the catalytic effect of titanium metal, which can facilitate the adhesion of soluble zirconium salts on the surface. At the same time, zirconium carbide is formed during the heating process. Zirconium carbide, as a material with great hardness and high melting point, can avoid the loss of carbon fiber during the later high-temperature heating process and improve the mechanical properties of the thermal insulation material;

[0021] 3) Zirconium carbide has a high affinity with zirconium oxide and silicon carbide added to the material, which is beneficial to the dispersion of short fibers in the material and avoids agglomeration, thereby reducing thermal conductivity and improving mechanical properties.

[0022] 4) The preparation process of the present invention has low cost, simple process, simple and efficient, and has the value of wide application. DETAILED DESCRIPTION

[0023] The present invention will be described in more detail below through specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0024] Embodiment 1:

[0025] 1) taking short chopped carbon fibers with a diameter of 5 μm and a length of 1 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1, then washing them with ethanol for 3 times, and drying them to obtain pretreated carbon fibers;

[0026] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 500 nm were ball-milled and mixed evenly in a mass ratio of 100:10, wherein the ball-to-material ratio was 3:1, the rotation speed was 100 r / min, and the ball milling was performed for 10 hours, and then placed in a tubular furnace, heated to 1000°C under nitrogen protection and calcined at high temperature for 6 hours; cooled to 550°C, acetylene gas was introduced, wherein the flow rate of acetylene gas was 150 ml / min, and the mixture was kept warm for 3 hours, and naturally cooled to room temperature and taken out;

[0027] 3) The product of step 2 is immersed in a zirconium nitrate solution with a concentration of 8wt% for 6 hours, taken out and dried, and then placed in a tube furnace, heated to 550°C and calcined for 6 hours under nitrogen protection, and then taken out and crushed after cooling to room temperature to obtain a carbon fiber with a titanium carbide layer, a carbon layer and a zirconium carbide layer coated on the surface in sequence;

[0028] 4) Mix zirconium oxide powder with an average particle size of 30 microns, silicon carbide powder with an average particle size of 30 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 in a mass ratio of 80:80:30:15:3 and disperse them in ethanol, adjust the solid content to 40wt%, place the dispersed slurry in a mold, dry, and hot press for 30 minutes to shape, the hot pressing temperature is 80°C, and the pressure is 32MPa; place the shaped embryo in a tubular furnace, heat to 1200°C and calcine for 8h under nitrogen protection, then heat to 2000°C and calcine for 2h, then cool to 500°C and anneal for 1h to obtain a short fiber hard thermal insulation composite material.

[0029] Embodiment 2:

[0030] 1) taking short chopped carbon fibers with a diameter of 8 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.5, then washing them with ethanol for 5 times, and drying them to obtain pretreated carbon fibers;

[0031] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 1000 nm were ball-milled and mixed uniformly in a mass ratio of 100:15, wherein the ball-to-material ratio was 5:1, the rotation speed was 150 r / min, and the ball milling was performed for 6 h, and then placed in a tubular furnace, heated to 1200°C under nitrogen protection and calcined for 4 h; cooled to 650°C, acetylene gas was introduced, wherein the flow rate of acetylene gas was 150 ml / min, and the mixture was kept warm for 0.5 h, and naturally cooled to room temperature and taken out;

[0032] 3) The product of step 2 is immersed in a zirconium nitrate solution with a concentration of 12wt% for 3 hours, taken out and dried, and then placed in a tube furnace, heated to 650°C and calcined for 4 hours under nitrogen protection, and then taken out and crushed after cooling to room temperature to obtain a carbon fiber with a titanium carbide layer, a carbon layer and a zirconium carbide layer coated on the surface in sequence;

[0033] 4) Mix zirconium oxide powder with an average particle size of 50 microns, silicon carbide powder with an average particle size of 50 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 in a mass ratio of 100:100:50:20:5 and disperse them in ethanol, adjust the solid content to 60wt%, place the dispersed slurry in a mold, dry, and hot press for 30 minutes to shape, the hot pressing temperature is 90°C, and the pressure is 32MPa; place the shaped embryo body in a tubular furnace, heat to 1400°C and calcine for 6h under nitrogen protection, then heat to 2000°C and calcine for 1h, then cool to 500-600°C and anneal for 0.5h to obtain a short fiber hard thermal insulation composite material.

[0034] Embodiment 3:

[0035] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0036] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 800 nm were ball-milled and mixed uniformly in a mass ratio of 100:12, wherein the ball-to-material ratio was 4:1, the rotation speed was 120 r / min, and the ball milling was performed for 8 h, and then placed in a tubular furnace, heated to 1100°C under nitrogen protection and calcined at high temperature for 5 h; cooled to 600°C, acetylene gas was introduced, wherein the flow rate of acetylene gas was 120 ml / min, and the mixture was kept warm for 1 h, and naturally cooled to room temperature and taken out;

[0037] 3) The product of step 2 is immersed in a zirconium nitrate solution with a concentration of 10wt% for 5 hours, taken out and dried, and then placed in a tube furnace, heated to 600°C and calcined for 5 hours under nitrogen protection, and then taken out and crushed after cooling to room temperature to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer;

[0038] 4) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0039] Comparative Example 1 (without titanium metal modification)

[0040] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0041] 2) The pretreated carbon fiber was placed in a tubular furnace, heated to 600°C under nitrogen protection, acetylene gas was introduced at a flow rate of 120 ml / min, the temperature was kept for 1 hour, and the mixture was naturally cooled to room temperature and taken out;

[0042] 3) The product of step 2 is immersed in a zirconium nitrate solution with a concentration of 10wt% for 5 hours, taken out and dried, and then placed in a tube furnace, heated to 600°C and calcined for 5 hours under nitrogen protection, and then taken out and crushed after cooling to room temperature to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer;

[0043] 4) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0044] Comparative Example 2 (without carbon coating)

[0045] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0046] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 800 nm were ball-milled and mixed uniformly in a mass ratio of 100:12, wherein the ball-to-material ratio was 4:1, the rotation speed was 120 r / min, and the ball milling was performed for 8 h. Then, the mixture was placed in a tubular furnace, heated to 1100° C. and calcined for 5 h under nitrogen protection, and then naturally cooled to room temperature and taken out;

[0047] 3) The product of step 2 is immersed in a zirconium nitrate solution with a concentration of 10wt% for 5 hours, taken out and dried, and then placed in a tube furnace, heated to 600°C and calcined for 5 hours under nitrogen protection, and then taken out and crushed after cooling to room temperature to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer;

[0048] 4) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0049] Comparative Example 3 (without zirconium carbide coating)

[0050] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0051] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 800 nm were ball-milled and mixed uniformly in a mass ratio of 100:12, wherein the ball-to-material ratio was 4:1, the rotation speed was 120 r / min, and the ball milling was performed for 8 h, and then placed in a tubular furnace, heated to 1100°C under nitrogen protection and calcined at high temperature for 5 h; cooled to 600°C, acetylene gas was introduced, wherein the flow rate of acetylene gas was 120 ml / min, and the mixture was kept warm for 1 h, and naturally cooled to room temperature and taken out;

[0052] 3) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 2 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0053] Comparative Example 4 (without titanium metal modification and carbon coating)

[0054] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0055] 2) soaking the product of step 1 in a 10wt% zirconium nitrate solution for 5 hours, taking it out and drying it, then placing it in a tube furnace, heating it to 600°C under nitrogen protection and calcining it for 5 hours, cooling it to room temperature and then taking it out and crushing it to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer;

[0056] 3) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 2 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0057] Comparative Example 5 (without carbon coating and zirconium carbide coating)

[0058] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0059] 2) The pretreated carbon fiber and titanium metal powder with a particle size of 800 nm were ball-milled and mixed uniformly in a mass ratio of 100:12, wherein the ball-to-material ratio was 4:1, the rotation speed was 120 r / min, and the ball milling was performed for 8 h. Then, the mixture was placed in a tubular furnace and heated to 1100° C. and calcined for 5 h under nitrogen protection. The mixture was naturally cooled to room temperature and taken out.

[0060] 3) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 2 are dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7h under nitrogen protection, then heated to 2000°C and calcined for 1h, and then cooled to 550°C and annealed for 1h to obtain a short fiber hard thermal insulation composite material.

[0061] Comparative Example 6 (pure carbon fiber)

[0062] 1) taking short chopped carbon fibers with a diameter of 6 μm and a length of 2 mm, dispersing them in a mixed solution of acetone and tetrahydrofuran in a mass ratio of 1:1.2, then washing them with ethanol for 4 times, and drying them to obtain pretreated carbon fibers;

[0063] 2) zirconium oxide powder with an average particle size of 40 microns, silicon carbide powder with an average particle size of 40 microns, carbon fiber obtained in step 1, phenolic resin and silane coupling agent are mixed and dispersed in ethanol in a mass ratio of 90:90:40:18:4, and the solid content is adjusted to 50wt%. The dispersed slurry is placed in a mold, dried, and hot-pressed for 20 minutes to shape. The hot-pressing temperature is 85°C and the pressure is 32MPa; the shaped embryo is placed in a tubular furnace, heated to 1300°C and calcined for 7 hours under nitrogen protection, then heated to 2000°C and calcined for 1 hour, and then cooled to 550°C and annealed for 1 hour to obtain a short fiber hard thermal insulation composite material.

[0064] Test Data

[0065] The product performances of the embodiments and comparative examples of the present invention were tested, and the results are shown in Table 1.

[0066] Table 1

[0067]

[0068]

[0069] By adjusting the process in the comparative example, it is intended to prove the influence of various process parameters on product performance. The product prepared by the method of the present invention has good thermal insulation performance and good mechanical strength.

[0070] By comparing the embodiment and comparative example 6, it can be seen that the modification of carbon fiber by the present invention greatly improves the mechanical properties of the product, and at the same time, the thermal insulation performance is also significantly improved. From the results of comparative example 1, it can be seen that the carbon fiber is modified with titanium metal. The metal on the surface of the carbon fiber can act as a catalyst to promote the deposition of carbon during carbon deposition, thereby improving the deposition effect, and partially forming titanium carbide hard alloy to improve the strength of the carbon fiber. From the results of comparative examples 2 and 4, it can be seen that the carbon layer has a significant promoting effect on the formation of the zirconium carbide layer. Since the carbon layer has a high specific surface area, it can be beneficial for the soluble zirconium salt to adhere to the surface, and at the same time, zirconium carbide is formed during the heating process. From the results of comparative examples 3 and 5, it can be seen that zirconium carbide, as a material with great hardness and high melting point, can avoid the loss of carbon fiber during the later high-temperature heating process, thereby improving the mechanical properties of the thermal insulation material. Zirconium carbide has a high affinity with zirconium oxide and silicon carbide added to the material, which is beneficial to the dispersion of short fibers in the material, avoiding agglomeration, thereby reducing thermal conductivity and improving mechanical properties.

[0071] Although the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as limiting the present invention.

Claims

1. An efficient preparation process for a short fiber rigid thermal insulation composite material, characterized in that: The method comprises: 1) taking chopped carbon fibers, dispersing them in a mixed solution of acetone and tetrahydrofuran, washing, and drying to obtain pretreated carbon fibers; 2) The pretreated carbon fiber and titanium metal nanopowder are mixed evenly, and then placed in a tube furnace, heated to 1000-1200° C. under a protective atmosphere for calcination; cooled to 550-650° C., acetylene gas is introduced, kept warm for a predetermined time, cooled to room temperature and taken out; 3) soaking the product of step 2 in a zirconium salt solution, taking it out and drying it, then placing it in a tube furnace, heating it to 550-650° C. under a protective atmosphere, calcining it, cooling it to room temperature, taking it out and crushing it to obtain a carbon fiber whose surface is sequentially coated with a titanium carbide layer, a carbon layer and a zirconium carbide layer; 4) Dispersing zirconium oxide powder, silicon carbide powder, carbon fiber obtained in step 3, phenolic resin and silane coupling agent in ethanol, drying, and hot pressing to shape; placing the shaped embryo body in a tubular furnace, heating to 1200-2200° C. for calcination under a protective atmosphere, and then cooling to 500-600° C. for annealing to obtain a short fiber hard thermal insulation composite material.

2. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 1 is characterized by: In the step 1, the diameter of the chopped carbon fiber is 5-8 μm and the length is 1-2 mm; the mass ratio of acetone to tetrahydrofuran is 1:1-1.

5.

3. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 1 is characterized by: In the step 2, the pretreated carbon fiber and the titanium metal powder are mixed in a mass ratio of 100:10-15, and the particle size of the titanium metal powder is 500-1000 nm.

4. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 3 is characterized by: In step 2, the high temperature calcination temperature is 1000-1200° C. for 4-6 hours in a tubular furnace under nitrogen protection; then the temperature is lowered to 550-650° C., acetylene gas is introduced at a flow rate of 100-150 ml / min, and the temperature is kept for 0.5-3 hours.

5. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 1 is characterized by: In step 3, the concentration of the zirconium nitrate solution is 8-12 wt %, and the soaking time is 3-6 h.

6. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 5 is characterized by: In the step 3, the calcination temperature in the tubular furnace under nitrogen protection is 550-650° C., and the calcination time is 4-6 hours.

7. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 1 is characterized by: In the step 4, zirconium oxide powder with an average particle size of 30-50 microns, silicon carbide powder with an average particle size of 30-50 microns, carbon fiber, phenolic resin and silane coupling agent obtained in step 3 are mixed and dispersed in ethanol in a mass ratio of 80-100:80-100:30-60:15-20:3-5, and the solid content is adjusted to 40-60wt%.

8. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 7 is characterized by: In step 4, the hot pressing temperature is 80-90° C., the hot pressing time is 10-30 min, and the hot pressing pressure is 30-35 MPa.

9. The efficient preparation process of the short fiber rigid thermal insulation composite material according to claim 1 is characterized by: In step 4, the shaped embryo body is placed in a tubular furnace, heated to 1200-1400° C. and calcined for 6-8 hours under nitrogen protection, then heated to 2000-2200° C. and calcined for 1-2 hours, then cooled to 500-600° C. and annealed for 0.5-1 hour to obtain a short fiber rigid thermal insulation composite material.

10. A short fiber rigid thermal insulation composite material, characterized by: The material is prepared by the process described in any one of claims 1 to 9.

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