粉末冶金铍铝合金相界面微观应力场的有限元分析

针对粉末冶金铍铝合金建立铍颗粒球形粒子填充铝基复合材料有限元模型,采用线弹性轴对称有限单元,计算铍铝合金复合材料在拉压两种情况下铍粒子与铝基体界面处的应力场,定性讨论界面脱粘、裂纹形成与扩展的力学原因。研究结果表明,在拉应力场中,第一主应力与von Mises应力在偏离赤道45°附近同时取得最大值,此处是界面最容易脱粘和屈服最先发生的区域;在压应力场中,von Mises应力与拉伸场相同,而第一主应力变化很小,法向应力在压缩场中变为负值;近界面的颗粒与基体受到此消彼长的法向应力相互作用。

Finite element analysis of microscopic stress on the interface bonding of powder metallurgy Be-Al alloy

As for powder metallurgy Be-Al alloy,the finite element model of Be particle-filled Al matrix composite was established.The stress field on the interface of Be particle and Al matrix under the tensile and compression conditions was calculated by using elastic axis￣systemtry finite element.The debonding,crack forming and crack propagation of interface were discussed.The results indicate that in the case of tensile stress,both of the first principal stress and the von Mises stress reach the maximum at the 45° from the equator of particle,where the interface is easiest to debond and plastic distort;in the case of compression stress,the distribution of von Mises stress is the same as that in the case of tensile stress,but the first principal stress has little change,and the normal stress is of minus.Particles near the interface and matrix are interacting under the reciprocal normal stress.