莫来石基陶瓷中柱状晶粒的断裂分析

本文制得了莫来石／莫来石（柱状）、ZTM／莫来石（柱状）类似于晶须增韧复合陶瓷显微结构的莫来石基陶瓷，并对柱状莫来石的断裂进行了研究和分析．莫来石柱状晶粒具有较高的强度，它的生长发育使材料的断裂由穿晶断裂为主变为穿晶、沿晶的混合型断裂，在断口中可观察到柱状莫来石的拔出现象；ZTM中ZrO₂相交在基体中产生压应力，增加了柱状莫来石和基体的界面结合力；使住状晶粒的界面解高困难，柱状莫来石的拔出效果减少，并且在高m－ZrO₂含量的材料中尤为显著．

Fracture Analysis of Rodlike Mullite Particles in Mullite Matrix Ceramics

Mullite/mullite (rodlike) and ZTM/mullite (rodlike) ceramics with the microstructure of whisker toughening ceramics were fabricated. The research and analysis demonstrated that rodlike mullite particles had relatively high fracture strength; The growth of rodlike particles changed the fracture mode from the mainly transgranular to the mixture type of transgranular and inter granular in monophase mullite ceramics. A lot of rodlike particles pull-out from the matrix were observed in the fracture surface of the specimens. For ZTM, compressive stresses in the matrix would be produced by the phase transformation of ZrO2. So the bonding forces among the rodlike particles and matrix were enhanced and the debonding of rodlike particles became difficult. The pull-out of rodlike particles from matrix became less in the fracture surfaces and this phenomenon was even more obvious for the specimen with high m-ZrO2 content.