形状记忆合金的力学及界面参数和体积分数对大块金属玻璃基复合材料增韧的影响

Effects of mechanics and interface parameters and volume fraction of shape memory alloys on toughening of bulk metallic matrix glass composites

采用考虑塑性的超弹性材料模型和基于损伤塑性的准脆性材料模型,建立了三维单胞有限元模型,模拟了形状记忆合金颗粒增韧大块金属玻璃基复合材料的单调拉伸行为。讨论了形状记忆合金的力学参数、体积分数、界面厚度和界面材料参数对金属玻璃增韧效果的影响。结果表明:提高形状记忆合金的相变应变和马氏体塑性屈服应力将显著提高形状记忆合金颗粒增韧大块金属玻璃基复合材料的拉伸失效应变;形状记忆合金弹性模量超过50.0GPa、马氏体塑性屈服应力超过1.8GPa后,复合材料的拉伸失效应变变化不大。能同时兼顾失效应变和失效应力的形状记忆合金体积分数为15%左右。复合材料界面弹性模量和界面屈服应力的增加将提高复合材料的失效应力,但对失效应变影响不大;复合材料界面厚度的增加在提高失效应变的同时,也降低了复合材料的失效应力。

Using superelasticity material model taking plasticity into consideration and quasi-brittle material model based on damage plasticity,a three-dimensional finite element unit cell model was established,and the monotonic tensile behaviors of shape memory alloy particle toughening bulk metallic glass matrix composites were simulated.The effects of mechanics parameters and volume fraction of shape memory alloys,along with interface thickness and interface material parameters on the toughening of bulk metallic glass were discussed.Results show that the increasing of the phase transformation strain of shape memory alloys and martensite plastic yield stress can improve the tensile failure strain of shape memory alloy particle toughening bulk metallic glass matrix composites significantly;meantime,the tensile failure strain changes little when the elastic modulus of shape memory alloys is beyond 50.0GPa and martensite plastic yield stress is over 1.8GPa.The reasonable volume fraction of shape memory alloy in balance of failure strain and failure stress is about 15%.The increasing of composites interfacial elastic modulus and interfacial yield stress can improve the failure stress of composites;however,the failure strain does not change a lot with them.The increasing of the thickness of composites interface can improve the failure strain while decreases the failure stress of composites.