Microstructural Evolution in In-Situ-Reinforced Silicon Carbide Ceramics

9523648附图拟议研究的目的是了解原位增强碳化硅(SIC)的微观结构演变。这是一种新型的韧性陶瓷，在无压液相烧结过程中，在显微组织中原位生长了细长的颗粒增强相。这项研究包括两组关键的实验研究：1)系统地研究了多晶液相烧结碳化硅的致密化和颗粒生长动力学；2)系统地研究了S过饱和Al-Y-O-C玻璃中生长的孤立的碳化硅颗粒的生长动力学。将尽可能参考现有模型，对实验结果进行严格分析，以确定致密化、正常晶粒生长和各向异性晶粒生长的速率控制机制。%预计，拟议的研究将提供ISR碳化硅中微结构演变的全面图景，这对于有效地调整机械性能至关重要。此外，这项研究还有可能有助于实现更广泛的目标，即指导一般工艺努力，创造具有新颖微结构的下一代ISR陶瓷，以获得优异的机械性能。***

9523648 Padture The objective of the proposed research is to understand the aspects of microstructural evolution in in situ-reinforced (ISR) silicon carbide (SiC). This is a new class of tough ceramics in which elongated-grain reinforcements are grown in situ within the microstructure during pressureless liquid- phase sintering. The proposed research consists of two sets of critical experimental studies: 1) a systematic study of densification and grain--growth kinetics in polycrystalline liquid-phase sintered SiC, and 2) a systematic study of growth kinetics of isolated SiC grains grown in s supersaturated Al-Y-O-C glass. The results of the experiments will be critically analyzed, with reference to existing models whenever possible, to determine the rate- controlling mechanisms for densification, normal grain growth and anisotropic grain growth. %%% It is anticipated that the proposed study will provide a comprehensive picture of the evolution of the microstructures in ISR SiC an understanding vital to the effective tailoring of mechanical properties. In addition, the research also has the potential to contribute toward a broader goal of guiding general processing efforts for creating the next generation of ISR ceramics with novel microstructures for superior mechanical properties. ***