SIC/ZRC COMPOSITE FIBER, PREPARATION METHOD AND USE THEREOF

Abstract

Provided are a SiC/ZrC composite fiber, a preparation method and use thereof. The SiC/ZrC composite fiber has a diameter of 10 to 70 μm. The method includes mixing liquid polycarbosilane with a zirconium-containing polymer to obtain a hybrid spinning solution, and then performing electrospinning to obtain a SiC/ZrC composite fiber precursor, crosslinking and thermally treating the SiC/ZrC composite fiber precursor in a protective atmosphere to obtain the SiC/ZrC composite fiber. The SiC/ZrC composite fiber is continuous and uniform, has an adjustable diameter, and thus has outstanding tensile strength and breaking strength and excellent high-temperature resistance. Without use of any organic solvent or spinning agent, the method achieves short process flow and high yield, indicating wide application prospects.

Claims

1. A SiC/ZrC composite fiber, wherein the SiC/ZrC composite fiber has a diameter of 10 to 70 μm.

2. The SiC/ZrC composite fiber according to claim 1, wherein the diameter of the SiC/ZrC composite fiber is 12 to 40 μm.

3. A preparation method of the SiC/ZrC composite fiber according to claim 1, comprising steps of: (1) under protection of an inert atmosphere, mixing liquid polycarbosilane with a zirconium-containing polymer to obtain a hybrid spinning solution, and performing electrospinning to obtain a SiC/ZrC composite fiber precursor; and (2) crosslinking and thermally treating the SiC/ZrC composite fiber precursor obtained in step (1) in a protective atmosphere to obtain the SiC/ZrC composite fiber.

4. The preparation method according to claim 3, wherein the zirconium-containing polymer in step (1) comprises any one of or a combination of at least two of polyzirconoxane, zirconium acetylacetonate, or tetraallylamine zirconium.

5. The preparation method according to claim 3, wherein a mass ratio of the liquid polycarbosilane to the zirconium-containing polymer in step (1) is (1-5):1.

6. The preparation method according to claim 3, wherein the mixing in step (1) comprises glass rod stirring, magnetic stirring or mechanical stirring.

7. The preparation method according to claim 3, wherein the mixing in step (1) is for a period of 1 to 5 hours.

8. The preparation method according to claim 3, wherein the hybrid spinning solution in step (1) has a viscosity of 0.5 to 10 Pa.Math.s.

9. The preparation method according to claim 3, wherein the electrospinning in step (1) is carried out at a voltage of 10 to 30 kV.

10. The preparation method according to claim 3, wherein an injection flow rate for the electrospinning in step (1) is 1 to 5 mL/h.

11. The preparation method according to claim 3, wherein a fiber collecting distance for the electrospinning in step (1) is 5 to 20 cm.

12. The preparation method according to claim 3, wherein the electrospinning in step (1) is for a period of 1 to 10 hours.

13. The preparation method according to claim 3, wherein a heating rate for the crosslinking in step (2) is 1 to 5° C./min.

14. The preparation method according to claim 3, wherein a temperature for the crosslinking in step (2) is 100 to 180° C.

15. The preparation method according to claim 3, wherein the crosslinking in step (2) is for a period of 1 to 5 hours.

16. The preparation method according to claim 3, wherein a temperature for the thermal treatment in step (2) is 1300 to 1800° C.

17. The preparation method according to claim 3, wherein a heating rate for the thermal treatment in step (2) is 1 to 15° C./min.

18. The preparation method according to claim 3, wherein the thermal treatment in step (2) is for a period of 1 to 5 hours.

19. The preparation method according to claim 3, comprising steps of: (1) preparing a hybrid spinning solution of liquid polycarbosilane and a zirconium-containing polymer in a mass ratio of (1-5):1 at 18 to 25° C., and magnetically stirring the solution for 1 to 5 hours to obtain a hybrid spinning solution with a viscosity of 0.5 to 10 Pa.Math.s; (2) charging the hybrid spinning solution obtained in step (1) into a glass injector before electrospinning for 1 to 10 hours under conditions including an output voltage of 10 to 30 kV, an injection flow of 1 to 5 mL/h and a fiber collecting distance on a flat aluminum foil of 5 to 20 cm, so as to obtain a SiC/ZrC composite fiber precursor; and (3) heating the SiC/ZrC composite fiber precursor obtained in step (2) to 100 to 180° C. at a rate of 1 to 5° C./min in a protective atmosphere for crosslinking for 1 to 5 hours, and finally heating to 1300 to 1800° C. at a rate of 1 to 15° C./min in the protective atmosphere for high-temperature thermal treatment for 1 to 5 hours to obtain the SiC/ZrC composite fiber.

20. A method of using the SiC/ZrC composite fiber according to claim 1 in an aircraft, a solar thermoelectric receiver and a nuclear fuel cladding.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0044] FIG. 1 is an XRD diagram of a SiC/ZrC composite fiber prepared in Example 1.

[0045] FIG. 2 is an SEM diagram of the SiC/ZrC composite fiber prepared in Example 1.

[0046] FIG. 3 is a stress-strain curve of the SiC/ZrC composite fiber prepared in Example 1.

DETAILED DESCRIPTION

[0047] The technical solutions of the present invention will be further described below through specific embodiments in conjunction with the drawings. Embodiments set forth below are merely simple examples of the present invention, and are not intended to represent or limit the protection scope of the present invention. The protection scope of the present invention is defined by the claims.

Example 1

[0048] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0049] (1) A hybrid spinning solution of liquid polycarbosilane and polyzirconoxane in a mass ratio of 3:1 was prepared at 18° C., and then fully magnetically stirred for 3 hours to obtain the hybrid spinning solution with the viscosity of 4.8 Pa.Math.s.

[0050] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe before electrospinning for 6 hours under the conditions that the output voltage was 15 kV, the injection flow was 2.5 mL/h and the fiber collecting distance on a flat aluminum foil was 10 cm to obtain a SiC/ZrC composite fiber precursor.

[0051] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 120° C. at a rate of 2° C./min in an argon atmosphere for crosslinking for 3 hours, and finally heated to 1600° C. at a rate of 5° C./min under the protection of argon for high-temperature thermal treatment for 2 hours to obtain the SiC/ZrC composite fiber.

[0052] The diameter of the SiC/ZrC composite fiber prepared in this example was 12 μm, and its yield was 78%.

[0053] The SiC/ZrC composite fiber prepared in this example was characterized by X-ray Diffraction (XRD), and the characterization results are shown in FIG. 1. The figure shows the characteristic diffraction peaks of SiC and ZrC. There is almost no impurity phase. It is indicated that the SiC/ZrC composite fiber prepared in this example has great crystallinity and high purity.

[0054] The SiC/ZrC composite fiber prepared in this example was characterized by scanning electron microscopy (SEM), and the characterization results are shown in FIG. 2. As can be seen from the figure, the SiC/ZrC composite fiber is uniform and continuous.

[0055] The SiC/ZrC composite fiber prepared in this example was subjected to tensile strength testing. The test method was as follows: the strength of the composite fiber was tested by adopting a Shanghai JSF08 high-precision micro tester for mechanical properties of short fibers, where the gauge length was 10 mm and the elongation rate was 0.5 mm/min. The test results are shown in FIG. 3. As can be seen from the figure, the tensile strength increased with increasing strain. When the strain reached 1%, the tensile strength of the composite fiber was 1200 MPa, and when the strain continued to increase, the tensile strength of the composite fiber tends to be remarkably reduced until fracture.

Example 2

[0056] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0057] (1) A hybrid spinning solution of liquid polycarbosilane and zirconium acetylacetonate in a mass ratio of 3.5:1 was prepared at the temperature of 20° C., and then fully magnetically stirred for 4 hours to obtain the hybrid spinning solution with the viscosity of 3.4 Pa.Math.s.

[0058] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe, before electrospinning for 5 hours under the conditions that the output voltage was 15 kV, the injection flow was 2 mL/h and the fiber collecting distance on a flat aluminum foil was 15 cm to obtain a SiC/ZrC composite fiber precursor.

[0059] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 140° C. at a rate of 2° C./min in an argon atmosphere for crosslinking for 2 hours, and finally heated to 1550° C. at a rate of 5° C./min under the protection of argon for high-temperature thermal treatment for 2 hours to obtain the SiC/ZrC composite fiber.

[0060] The diameter of the SiC/ZrC composite fiber prepared in this example was 18 μm, and its yield was 73%.

Example 3

[0061] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0062] (1) ‘A hybrid spinning solution of liquid polycarbosilane and polyzirconoxane in a mass ratio of 4:1 was prepared at the temperature of 22° C., and then fully magnetically stirred for 2 hours to obtain the hybrid spinning solution with the viscosity of 2.1 Pa.Math.s.

[0063] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe before electrospinning for 5 hours under the conditions that the output voltage was 15 kV, the injection flow was 1.5 mL/h and the fiber collecting distance on a flat aluminum foil was 10 cm to obtain a SiC/ZrC composite fiber precursor.

[0064] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 120° C. at a rate of 5° C./min in an argon atmosphere for crosslinking for 3 hours, and finally heated to 1500° C. at a rate of 8° C./min under the protection of argon for high-temperature thermal treatment for 3 hours to obtain the SiC/ZrC composite fiber.

[0065] The diameter of the SiC/ZrC composite fiber prepared in this example was 30 μm, and its yield was 68%.

Example 4

[0066] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0067] (1) A hybrid spinning solution of liquid polycarbosilane and polyzirconoxane in a mass ratio of 4.5:1 was prepared at the temperature of 25° C., and then fully magnetically stirred for 4 hours to obtain the hybrid spinning solution with the viscosity of 1.3 Pa.Math.s.

[0068] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe before electrospinning for 4 hours under the conditions that the output voltage was 15 kV, the injection flow was 2.5 mL/h and the fiber collecting distance on a flat aluminum foil was 15 cm to obtain a SiC/ZrC composite fiber precursor.

[0069] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 140° C. at a rate of 2° C./min in an argon atmosphere for crosslinking for 4 hours, and finally heated to 1600° C. at a rate of 5° C./min under the protection of argon for high-temperature thermal treatment for 2 hours to obtain the SiC/ZrC composite fiber.

[0070] The diameter of the SiC/ZrC composite fiber prepared in this example was 25 μm, and its yield was 72%.

Example 5

[0071] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0072] (1) A hybrid spinning solution of liquid polycarbosilane with polyzirconoxane and zirconium acetylacetonate in a mass ratio of 1:1 was prepared at the temperature of 20° C., where the mass ratio of polyzirconoxane to zirconium acetylacetonate was controlled to be 1:1, and then fully magnetically stirred for 1 hour to obtain the hybrid spinning solution with the viscosity of 10 Pa.Math.s.

[0073] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe before electrospinning for 1 hour under the conditions that the output voltage was 10 kV, the injection flow was 1 mL/h and the fiber collecting distance on a flat aluminum foil was 5 cm to obtain a SiC/ZrC composite fiber precursor.

[0074] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 100° C. at a rate of 5° C./min in a hydrogen atmosphere for crosslinking for 1 hour, and finally heated to 1800° C. at a rate of 8° C./min under the protection of hydrogen for high-temperature thermal treatment for 1 hour to obtain the SiC/ZrC composite fiber.

[0075] The diameter of the SiC/ZrC composite fiber prepared in this example was 68 μm, and its yield was 62%.

Example 6

[0076] This example provides a preparation method of a SiC/ZrC composite fiber. The method includes the following steps.

[0077] (1) A hybrid spinning solution of liquid polycarbosilane and tetraallylamine zirconium in a mass ratio of 5:1 was prepared at the temperature of 25° C., and then fully magnetically stirred for 5 hours to obtain the hybrid spinning solution with the viscosity of 0.5 Pa.Math.s.

[0078] (2) The hybrid spinning solution obtained in step (1) was charged into a glass syringe before electrospinning for 10 hours under the conditions that the output voltage was 30 kV, the injection flow was 5 mL/h and the fiber collecting distance on a flat aluminum foil was 20 cm to obtain a SiC/ZrC composite fiber precursor.

[0079] (3) The SiC/ZrC composite fiber precursor obtained in step (2) was heated to 180° C. at a rate of 2° C./min in a nitrogen atmosphere for crosslinking for 5 hours, and finally heated to 1300° C. at a rate of 5° C./min under the protection of nitrogen for high-temperature thermal treatment for 5 hours to obtain the SiC/ZrC composite fiber.

[0080] The diameter of the SiC/ZrC composite fiber prepared in this example was 40 μm, and its yield was 65%.

Example 7

[0081] This example is only different from Example 1 in that the thermal treatment in step (3) was 1100° C.

[0082] The SiC/ZrC composite fiber prepared in this example contained a larger amount of amorphous phases. The diameter of the fiber was 55 μm, and its yield was 54%.

Example 8

[0083] This example is only different from Example 1 in that the thermal treatment in step (3) was 2000° C.

[0084] The SiC/ZrC composite fiber prepared in this example was not continuous and even fractured. The diameter of the fiber was 80 μm, and its yield was 67%.

[0085] Evaluation of SiC/ZrC Performances:

[0086] The SiC/ZrC composite fibers prepared in the above examples and the SiC/ZrC composite material prepared in Comparative Example 1 were subjected to testing in terms of tensile strength, breaking strength and high temperature resistance. The test method was as follows: the strength of the composite fiber was tested by adopting a Shanghai JSF08 high-precision micro tester for mechanical properties of short fibers, where the gauge length was 10 mm and the elongation rate was 0.5 mm/min.

[0087] The tensile strength and breaking strength were tested as described in Example 1.

[0088] The high temperature resistance was tested by using a NETZSCH STA 449C thermal analyzer. The test atmosphere was air, and the heating rate was 5° C./min.

[0089] The test results are shown in Table 1.

TABLE-US-00001 TABLE 1 Tensile Breaking Temperature Diameter Strength Strength Tolerance (μm) (MPa) (MPa) (° C.) Example 1 12 1200 900 1100 Example 2 18 1100 740 1100 Example 3 30 880 650 1000 Example 4 25 1000 830 1050 Example 5 68 640 500 920 Example 6 40 760 530 1000 Example 7 55 720 515 950 Example 8 80 480 290 900

[0090] The following points can be seen from Table 1.

[0091] (1) It can be seen from Examples 1 to 8 that for the SiC/ZrC composite fiber obtained in the Examples 1 to 8 by mixing the main raw material, i.e., liquid polycarbosilane, with the zirconium-containing polymer to obtain the hybrid spinning solution, spinning using the electrospinning technology and then performing crosslinking and high-temperature thermal treatment, the diameter was 12 to 80 μm, the tensile strength was 480 to 1200 MPa, the breaking strength was 290 to 900 MPa, and the temperature tolerance was 900 to 1100° C. It is indicated that the SiC/ZrC composite fibers prepared in Examples 1 to 8 possess a controllable diameter and excellent tensile strength, breaking strength and high-temperature resistance.

[0092] (2) It can be seen from Example 1 and examples 7 and 8 that the SiC/ZrC composite fiber obtained in Example 1 at a high-temperature thermal treatment temperature of 1600° C. were more uniform and continuous and have higher crystallinity of the two phases of SiC/ZrC than those of Examples 7 and 8 obtained at the thermal treatment temperature of 1100° C. and 2000° C. respectively, and that, in addition, the tensile strength was 1200 MPa, 720 MPa and 480 MPa respectively, the breaking strength was 900 MPa, 515 MPa and 290 MPa respectively, and the temperature resistance was 1100° C., 950° C. and 900° C. respectively. It is indicated that the tensile strength, breaking strength and high temperature resistance of the SiC/ZrC composite fiber prepared in Example 1 are better than those of the SiC/ZrC composite materials prepared in examples 7 and 8. It is further indicated that the temperature for high-temperature thermal treatment adopted in Example 1 is more favorable for obtaining the SiC/ZrC composite fiber with higher tensile strength, breaking strength and temperature resistance.

[0093] In conclusion, the SiC/ZrC composite fiber provided by the present invention is continuous and uniform, its diameter is adjustable, its highest tensile strength and breaking strength can reach 1200 MPa and 900 MPa respectively, and the composite fiber can be resistant to 1100° C. The composite fiber thus has excellent tensile strength, breaking strength and high temperature resistance. Without addition of any organic solvent or spinning agent, the preparation method of the SiC/ZrC composite fiber provided by the present invention has the advantages of short preparation process flow, mild conditions, a ceramic conversion rate of more than 62%, and easy industrialization. Therefore, the method has wide application prospects.

[0094] The applicant has stated that although the detailed structure characteristics of the present invention are described through the embodiments described above, the present invention is not limited to the detailed structure characteristics described above, which means that implementation of the present invention does not necessarily depend on the detailed structure characteristics described above. It should be apparent to those skilled in the art that any improvements made to the present invention, equivalent replacements of units selected in the present invention and addition of assistant units thereof, and selections of specific methods, etc., all fall within the protection scope and the disclosed scope of the present invention.