晶须转动及其对SiC_W／Al－Ni复合材料高温压缩变形流变应力的影响

ROTATION OF WHISKERS AND ITS EFFECT ON HIGH TEMPERATURE COMPRESSIVE FLOW STRESS OF SiC_W/Al-Ni COMPOSITE

本文测定了ＳｉＣＷ／Ａｌ－Ｎｉ复合材料高温压缩变形的应力－应变曲线，讨论了该种复合材料高温压缩变形时所表现出的应变软化现象，利用ＳＥＭ观察了ＳｉＣＷ／Ａｌ－Ｎｉ复合材料在高温压缩变形中晶须的转动，并对晶须长轴的取向分布函数及其与复合材料压缩流变应力之间的关系进行了较为详细的研究．研究结果表明，在压缩变形过程中，ＳｉＣＷ晶须的长轴要发生转动，并趋向垂直于压缩方向分布，晶须取向的重新分布是造成复合材料应变软化的主要原因．

The high temperature compressive deformation stress-strain curve was measured for a SiCW/ Al-Ni composite, and the effect of strain-softening of the composite during high temperature deformation was discussed. The rotation of logedutinal axis of the SiC whiskers was studied by SEM observation, and the orientation distribution function of SiC whiskers and the relationship between the function and compressive flow stress was also studied. The results indicated that the strain softening effect is mainly induced by the re-distribution of the whiskers