A kind of method that prepares beryllium-containing silicon carbide ceramic fiber by gallium bath

Abstract

The invention relates to a method for preparing beryllium-containing silicon carbide ceramic fibers through a gallium bath, and belongs to the technical field of silicon carbide fiber preparation. The present invention uses beryllium-containing SiC ceramic precursors as raw materials; through melt spinning, PBCS precursors are obtained; the PBCS precursors are subjected to non-melting treatment; the precursors after non-melting treatment are obtained; the precursors after non-melting treatment are processed gallium bath to obtain deoxidized precursors; the temperature of the gallium bath is 29.76-100° C.; the obtained deoxidized precursors are subjected to high temperature treatment to obtain finished products. The preparation process of the invention is reasonable, the obtained product has excellent performance, and is convenient for large-scale industrial application.

Description

technical field

[0001] The invention relates to a method for preparing beryllium-containing silicon carbide ceramic fibers through a gallium bath, and belongs to the technical field of silicon carbide fiber preparation. Background technique

[0002] SiC ceramics have excellent properties such as high strength, high modulus, high temperature resistance, corrosion resistance, oxidation resistance, and low density. In terms of performance, SiC ceramics are the material of choice for ultra-high temperature working parts, and have a wide range of uses in high-tech fields.

[0003] At present, the biggest problem that limits the improvement of the performance of SiC ceramics is: excessive growth of β-SiC grains at high temperatures. In order to solve this problem, the introduction of high melting point compounds or heterogeneous elements in the process of preparing SiC ceramic precursors to prepare SiC ceramics containing heterogeneous elements has become the mainstream of the de...

Examples

Embodiment 1

[0037] Taking PSCS (molecular weight is 160) and beryllium acetylacetonate as raw materials, the mass proportion of the two (the proportioning described in the following examples is the mass proportion) is beryllium acetylacetonate:PSCS=10:100, 420°C of reaction temperature, The pyrolysis temperature was 500°C, and after holding the reaction for 6 hours, it was dissolved in xylene and filtered, and the filtrate was distilled under reduced pressure at 350°C for 30 minutes to obtain PBCS with a softening point of 195°C and a beryllium content of 1.31wt%. PBCS was added to the melt spinning device and degassed under the protection of high-purity nitrogen, at 258 ° C, 4 × 10 5 Under the pressure of Pa, melt spinning at a speed of 300m / min to obtain a PBCS precursor with a diameter of 20μm; place the above fiber in a non-melting treatment device, and heat it to 185°C at a heating rate of 10°C per hour in an air atmosphere. ℃, keep warm for 2 hours, and cool to room temperature to o...

Embodiment 2

[0041] Other conditions are consistent with embodiment 1; the difference is:

[0042] The PBCS infusible fibers were placed in a metal gallium solution at 80°C; ultrasonicated for 60 min under the condition of 45KHz; taken out to obtain deoxidized PBCS infusible fibers.

[0043] The obtained beryllium-containing silicon carbide fiber has a tensile strength of 2.68 GPa and an elastic modulus of 345 GPa.

Embodiment 3

[0045] Using PCS (molecular weight 300) and beryllium as raw materials, beryllium: PCS = 5:100, the reaction temperature is 430 ° C, the cracking temperature is 490 ° C, and the reaction time is 4h, dissolved in xylene, and filtered, and the filtrate is at 350 ° C. ℃ for 1 hour under reduced pressure to obtain PBCS with a softening point of 202 ℃ and 0.61 wt% beryllium; PBCS was added to the melt spinning device and degassed under the protection of high-purity nitrogen, at 268 ℃, 4.5 × 10 5 Under Pa pressure, melt spinning at a speed of 350 m / min to obtain PBCS precursors with a diameter of 18 μm; the above fibers are placed in an infusible treatment device, and heated to 180 °C at a heating rate of 10 °C per hour in an air atmosphere. ℃, kept for 2 hours, and cooled to room temperature to obtain PBCS non-melting fibers;

[0046] The PBCS infusible fibers were placed in a metal gallium solution at 90°C; treated for 120 min; taken out to obtain deoxidized PBCS infusible fibers;...

technical field

[0001] The invention relates to a method for preparing beryllium-containing silicon carbide ceramic fibers through a gallium bath, and belongs to the technical field of silicon carbide fiber preparation. Background technique

[0002] SiC ceramics have excellent properties such as high strength, high modulus, high temperature resistance, corrosion resistance, oxidation resistance, and low density. In terms of performance, SiC ceramics are the material of choice for ultra-high temperature working parts, and have a wide range of uses in high-tech fields.

[0003] At present, the biggest problem that limits the improvement of the performance of SiC ceramics is: excessive growth of β-SiC grains at high temperatures. In order to solve this problem, the introduction of high melting point compounds or heterogeneous elements in the process of preparing SiC ceramic precursors to prepare SiC ceramics containing heterogeneous elements has become the mainstream of the de...

Examples

Embodiment 1

[0037] Taking PSCS (molecular weight is 160) and beryllium acetylacetonate as raw materials, the mass proportion of the two (the proportioning described in the following examples is the mass proportion) is beryllium acetylacetonate:PSCS=10:100, 420°C of reaction temperature, The pyrolysis temperature was 500°C, and after holding the reaction for 6 hours, it was dissolved in xylene and filtered, and the filtrate was distilled under reduced pressure at 350°C for 30 minutes to obtain PBCS with a softening point of 195°C and a beryllium content of 1.31wt%. PBCS was added to the melt spinning device and degassed under the protection of high-purity nitrogen, at 258 ° C, 4 × 10 5 Under the pressure of Pa, melt spinning at a speed of 300m / min to obtain a PBCS precursor with a diameter of 20μm; place the above fiber in a non-melting treatment device, and heat it to 185°C at a heating rate of 10°C per hour in an air atmosphere. ℃, keep warm for 2 hours, and cool to room temperature to o...

Embodiment 2

[0041] Other conditions are consistent with embodiment 1; the difference is:

[0042] The PBCS infusible fibers were placed in a metal gallium solution at 80°C; ultrasonicated for 60 min under the condition of 45KHz; taken out to obtain deoxidized PBCS infusible fibers.

[0043] The obtained beryllium-containing silicon carbide fiber has a tensile strength of 2.68 GPa and an elastic modulus of 345 GPa.

Embodiment 3

[0045] Using PCS (molecular weight 300) and beryllium as raw materials, beryllium: PCS = 5:100, the reaction temperature is 430 ° C, the cracking temperature is 490 ° C, and the reaction time is 4h, dissolved in xylene, and filtered, and the filtrate is at 350 ° C. ℃ for 1 hour under reduced pressure to obtain PBCS with a softening point of 202 ℃ and 0.61 wt% beryllium; PBCS was added to the melt spinning device and degassed under the protection of high-purity nitrogen, at 268 ℃, 4.5 × 10 5 Under Pa pressure, melt spinning at a speed of 350 m / min to obtain PBCS precursors with a diameter of 18 μm; the above fibers are placed in an infusible treatment device, and heated to 180 °C at a heating rate of 10 °C per hour in an air atmosphere. ℃, kept for 2 hours, and cooled to room temperature to obtain PBCS non-melting fibers;

[0046] The PBCS infusible fibers were placed in a metal gallium solution at 90°C; treated for 120 min; taken out to obtain deoxidized PBCS infusible fibers;...