【摘要】 通过SEM中静载动态拉伸,原位观察和研究了搅拌铸造法制备的YAl2P/Mg-Li-Al基复合材料裂纹的萌生及扩展机制。结果表明,微裂纹萌生位置主要为复合材料的铸造缺陷处、复合材料的基体中以及颗粒/基体界面处,并以在复合材料基体中萌生为主。微裂纹的扩展主要在基体和YAl2颗粒/基体界面处进行。主裂纹的长大方向具有选择性,裂纹主要沿颗粒贫化区与颗粒富集区的交界处开裂,主裂纹扩展到一定程度后,试样全面失稳而迅速断裂。基体的断裂失效在YAl2P/Mg-Li-Al复合材料拉伸断裂过程中起很大作用。更多还原

【Abstract】 YAl2P/Mg-Li-Al composite was prepared by stir-casting.The mechanisms of the crack forming and the propagation were investigated during the dynamic tension under the static load by SEM.The results show that the microcracks appear at the casting defects,in the Mg-Li-Al matrix and on the interface of YAl2P/Mg-Li-Al composite.The microcracks propagated mainly in matrix or along the particle/matrix interface.The dominant crack is mainly developed along the boundary between the particle-dense regions and particle-free regions,and the samples lose the stability and fracture rapidly after the cracks propagating to some extent.The matrix failure may play a significant role in the failure mechanism of YAl2P/Mg-Li-Al composite.更多还原