延性相增韧的陶瓷材料中相界面对韧性的作用

EFFECT OF INTERFACE ON TOUGHNESS IN DUCTILE PHASE TOUGHENED CERAMIC MATERIALS

论述了相界面结合与延性相的几何形态之间的匹配关系对延性相增韧的陶瓷基复合材料韧性的影响。对于连续延性相,例如网状、纤维或片状的延性相,界面结合较弱对增韧非常有益,因为裂纹扩展过程中相界面可发生部分分离,使桥接裂纹的延性相发生很大的塑性变形,消耗大量能量。而对于颗粒状的延性相,由于其球形形状及小的连续程度,经常导致断裂时断口上的延性相被完全拔出,几乎没有发生塑性变形,增韧效果较差,因此强的相界面结合强度是非常重要的。

Effect of correlation between interfacial bonding and ductile phase geometry on toughening in ductile phase toughened ceramic matrix composites has been discussed. For the comparatively continuous ductile phase, such as ductile network, fibre or plate, comparatively weak interfacial bond strength is beneficial for toughening,because partial debonding of the brittle matrix-ductile phase interface during crack propagation can occur, which promote plastic deformation of the ductile phase and dissipate large amount of energies. For discrete particulate ductile phase toughened brittle materials,the spherical geometry and small gauge length of the ductile phase often result in the ductile phase pull-out wilh little plastic deformation during crack propagation,which is the main limitation to toughening. Thus strong bond strength is crucial.