含B2-CuZr相CuZr基块体金属玻璃复合材料应变速率敏感性的变化

通过应变速率跳跃模式下的单轴压缩试验，研究了含有不同体积分数B2-CuZr相的CuZr基块体金属玻璃复合材料的应变速率敏感性。研究结果发现，随着B2-CuZr相体积分数的增加，在3.7×10?5 s?1至3.7×10?3 s?1的应变速率范围中，该复合材料的应变速率敏感指数可由负值变化为正值。但是，对于B2-CuZr相体积分数高达约80%的复合材料，其应变速率敏感指数的正值仍然是反常的低。这一现象与B2-CuZr相自身力学行为所呈现的有限应变速率依赖性有关，是由于变形过程中B2-CuZr相的马氏体相变效应所致。研究结果显示，CuZr基块体金属玻璃复合材料的极限应变速率敏感性受制于B2-CuZr相。

Strain rate sensitivity variation in CuZr-based bulk metallic glass composites containing B2-CuZr phase

Strain rate sensitivity (SRS) of CuZr-based bulk metallic glass composites (BMGCs) containing a B2-CuZr phase with different volume fractions were investigated by performing uniaxial compression tests in a strain-rate-jump mode. It was found that the SRS exponents of the BMGCs could vary from negative to positive within the strain-rate range from 3.7×10?5 s?1 to 3.7×10?3 s?1 with increasing the B2-CuZr phase volume fraction. However, the positive SRS exponent of the BMGC with a higher B2-CuZr phase volume fraction of up to about 80% was still unexpectedly low. This was attributed to the limited strain-rate-dependence of mechanical behavior of the B2-CuZr phase, which was induced by the martensitic transformation effect of the phase during deformation. It appears that the SRS ceiling of the CuZr-based BMGCs is controlled by the B2-CuZr phase.