基于有限元计算的形状记忆合金-金属玻璃复合材料变形行为

Deformation behavior of shape memory alloy-metallic glass matrix composites based on finite element calculations

利用有限元模拟方法,研究了拉伸-卸载预应变对形状记忆合金-金属玻璃复合材料力学行为的影响及其内在机理。结果表明:预处理应变增加,形状记忆合金-金属玻璃复合材料的屈服强度及弹性应变极限均提高,但拉伸延展性急剧下降。预应变增加导致形状记忆合金颗粒第二次加载时的变形行为由典型的马氏体相变过渡为连续的马氏体相变,甚至表现为纯马氏体相的弹性变形。这一"相变效应"的减弱甚至消失,是形状记忆合金-金属玻璃复合材料经拉伸-卸载预处理后拉伸性能退化的直接原因。

The influence of tensile-unloading pre-strains on the mechanical behavior of shape memory alloymetal glass composites and its internal mechanism were studied by finite element simulations.Simulation results show that both the yield strength and the limit of the elastic strain of the composites increase with the pretreatment strain,but the tensile ductility decreases sharply.With increasing pretreatment strain,the subsequent deformation of shape memory alloy particles shifts from a classic martensite phase transformation to a continuous martensite transformation,and finally to a simple martensite elastic deformation.The weakening or even disappearance of the phase transformation effect leads directly to the deterioration in the tensile performance of the pretreated shape memory alloy-metallic glass matrix composite.