Study on Microstructure of Alumina Based Rare Earth Ceramic Composite

摘要

Analysis techniques such as SEM, TEM and EDAX were used to investigate the microstructure of rare earth reinforced Al_2O_3/(W, Ti)C ceramic composite. Chemical and physical compatibility of the composite was analyzed and in-terfacial microstructure was studied in detail. It is found that both Al_2O_3 and (W, Ti) C phases are interlaced with each other to form the skeleton structure in the composite. A small amount of pores and glass phases are observed inside the material which will inevitably influence the physical and mechanical property of the composite. Thermal residual stresses resulted from thermal expansion mismatch can then lead to the emergence of dislocations and microcracks. Interfaces and boundaries of different types are found to exist inside the Al_2O_3/(W, Ti)C rare earth ceramic composite, which is concerned with the addition of rare earth element and the extent of solid solution of ceramic phases.