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Liquid-phase sintering gel casting SiC ceramic valve material and preparation method thereof
The invention discloses a liquid-phase sintering gel casting SiC ceramic valve material and a preparation method thereof. The material is prepared by the following steps: preparing slurry from raw materials in proportion, carrying out gel-casting molding and carrying out normal-pressure liquid-phase sintering, carrying out heat preservation at a low-temperature stage of 400-800 DEG C, cracking organic matters in a gel-casting green body in argon to generate carbon, then carrying out heat preservation at 1400-1600 DEG C, carrying out in-situ reaction on the cracked carbon and added silicon powder to generate silicon carbide, prompting densification of SiC ceramic containing crystal whiskers or fibers, continuing heating, and preserving heat at 1750-1900 DEG C to enable Al2O3 and Y2O3 to react to form a YAG liquid phase, so that densification is promoted, and the synergistic toughening effect of YAG and whisker or fiber is exerted. According to the method, the problems that in a gel casting method, high-content carbon generated through organic matter cracking is not beneficial to Al2O3 and Y2O3 liquid phase densification, the content of reactive sintering free silicon is high, the SiC ceramic composite material containing whisker or fiber toughening is difficult to densify, and SiC ceramic anisotropy is caused by pressurized sintering crystal whisker or fiber orientation distribution can be solved.
本发明公开了一种液相烧结凝胶注模成型SiC陶瓷阀件材料及其制备方法。该材料是将原料按比例配置浆料，经凝胶注模成型制备，常压液相烧结制备的，在400‑800℃的低温阶段保温，将凝胶注模生坯中的有机物在氩气中裂解生成碳，然后在1400‑1600℃保温，使裂解碳与添加的硅粉原位反应生成碳化硅，促进含晶须或纤维增韧的SiC陶瓷复合材料致密化，继续升温，在1750‑1900℃之间保温，使Al2O3和Y2O3反应形成YAG液相，促进致密化，发挥YAG与晶须或纤维的协同增韧作用。本发明能够解决凝胶注模方法中有机物裂解产生较高含量的碳不利于Al2O3和Y2O3液相致密化、反应烧结游离硅含量高、含晶须或纤维增韧的SiC陶瓷复合材料难以致密化、以及加压烧结晶须或纤维取向分布导致的SiC陶瓷各向异性的问题。
Liquid-phase sintering gel casting SiC ceramic valve material and preparation method thereof
The invention discloses a liquid-phase sintering gel casting SiC ceramic valve material and a preparation method thereof. The material is prepared by the following steps: preparing slurry from raw materials in proportion, carrying out gel-casting molding and carrying out normal-pressure liquid-phase sintering, carrying out heat preservation at a low-temperature stage of 400-800 DEG C, cracking organic matters in a gel-casting green body in argon to generate carbon, then carrying out heat preservation at 1400-1600 DEG C, carrying out in-situ reaction on the cracked carbon and added silicon powder to generate silicon carbide, prompting densification of SiC ceramic containing crystal whiskers or fibers, continuing heating, and preserving heat at 1750-1900 DEG C to enable Al2O3 and Y2O3 to react to form a YAG liquid phase, so that densification is promoted, and the synergistic toughening effect of YAG and whisker or fiber is exerted. According to the method, the problems that in a gel casting method, high-content carbon generated through organic matter cracking is not beneficial to Al2O3 and Y2O3 liquid phase densification, the content of reactive sintering free silicon is high, the SiC ceramic composite material containing whisker or fiber toughening is difficult to densify, and SiC ceramic anisotropy is caused by pressurized sintering crystal whisker or fiber orientation distribution can be solved.
本发明公开了一种液相烧结凝胶注模成型SiC陶瓷阀件材料及其制备方法。该材料是将原料按比例配置浆料，经凝胶注模成型制备，常压液相烧结制备的，在400‑800℃的低温阶段保温，将凝胶注模生坯中的有机物在氩气中裂解生成碳，然后在1400‑1600℃保温，使裂解碳与添加的硅粉原位反应生成碳化硅，促进含晶须或纤维增韧的SiC陶瓷复合材料致密化，继续升温，在1750‑1900℃之间保温，使Al2O3和Y2O3反应形成YAG液相，促进致密化，发挥YAG与晶须或纤维的协同增韧作用。本发明能够解决凝胶注模方法中有机物裂解产生较高含量的碳不利于Al2O3和Y2O3液相致密化、反应烧结游离硅含量高、含晶须或纤维增韧的SiC陶瓷复合材料难以致密化、以及加压烧结晶须或纤维取向分布导致的SiC陶瓷各向异性的问题。
Liquid-phase sintering gel casting SiC ceramic valve material and preparation method thereof
一种液相烧结凝胶注模成型SiC陶瓷阀件材料及其制备方法
LI QISONG (author) / MU YUNCHAO (author) / HUANG QUAN (author) / ZHANG QIAN (author) / JIA SHAOPEI (author) / WANG ZHIXIN (author) / CHENG XIAOZHE (author) / GUAN XIAOYAN (author)
2021-05-25
Patent
Electronic Resource
Chinese
IPC:
C04B
Kalk
,
LIME
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