应变速率对Zr67.76Cu11.94Ni8.30Al12非晶复合材料力学性能及锯齿流变行为的影响

Effects of strain rates on mechanical properties and serrated flow behaviors of Zr67.76Cu11.94Ni8.30Al12 metallic glass compo

摘要:

摘要：本文采用统计学方法研究了应变速率对Zr67.76Cu11.94Ni8.30Al12非晶复合材料力学性能及锯齿流变行为的影响。结果表明：随着应变速率的增加，材料的塑性应变减小，抗压强度下降；同时应力降幅Δσ的锯齿分布从单调下降分布转变为峰状分布，应力降幅的频数由小应力降幅区间向大应力降幅区间过渡，单位塑性应变的锯齿频数M呈下降趋势，试棒侧面剪切带数量减少且相互交割、分支、阻止作用明显减弱，此时，能量耗散机制变差，能量积聚在材料内部，导致温度升高和剪切膨胀效应，造成试样断裂。

Abstract:

Abstract:The influences of strain rates on mechanical properties and serrated flow behaviors of Zr67.76Cu11.94Ni8.30Al12 metallic glass composite have been investigated in this paper with statistical methods. The results demonstrate that both the plastic strain and the compressive strength decreased with the increasing of strain rates;Meanwhile, the serrated distribution of stress drop (Δσs) changed from a monotonical decreasing into a peak-like shape, the absolute frequency of it ranged from small to large interval. The serrated number of units of plastic strain (M) continuously declined. Moreover, the number of the shear bands of sample reduced and the interaction among them significantly weakened. According to the changes all above, the energy dissipation mechanism deteriorates and the increasing of the temperature and the shear expansion effects due to the energy accumulation within the material resulting the specimen fracture catastrophically occur.