长径比和加载速率对铜基块体金属玻璃室温力学性能的影响

摘要

Room-temperature mechanical properties of Cu50Zr40Ti10−xNix(0≤x≤4,mole fraction,%) bulk metallic glasses (BMG) with aspect ratios in the range of 1:1−2.5:1 and loading rates in the range of1×10−5−1×10−2s−1were systematically investigated by room-temperatureuniaxialcompression test.In the condition of an aspect ratio of 1:1, the superplasticity can be clearly observed for Cu50Zr40Ti10BMG when the loading rate is1×10−4s−1, while for Cu50Zr40Ti10−xNix(x=1−3, mole fraction, %) BMGs when the loading rate is1×10−2s−1. The plastic strain (εp), yielding strength (σy) and fracture strength (σf) of the studied Cu-based BMGs significantly depend on the aspect ratio and the loading rate. In addition, theσyof the studied Cu-based BMGs with an aspect ratio of 1:1 is close to the σfof those with the other aspect ratios when the loading rate is1×10−2s−1. The mechanism for the mechanical response to the loading rate and the aspect ratiowas also discussed.%通过单向压缩实验在试样长径比(H/D)和加载速率分别为1：1~2.5：1和1×10−5~1×10−2 s−1的条件下对Cu50Zr40Ti10−xNix (0≤x≤4，摩尔分数，%)块体金属玻璃的室温力学性能进行了系统研究。在长径比为1：1的情况下，当加载速率为1×10−4 s−1时，Cu50Zr40Ti10块体金属玻璃表现出超塑性；而Cu50Zr40Ti10−xNix (x=1~3，摩尔分数，%)块体金属玻璃在加载速度为1×10−2 s−1的条件下出现超塑性；塑性应变(εp)、屈服强度(σy)和断裂强度(σf)显著地依赖于长径比和加载速率；当加载速率为1×10−2 s−1时，长径比为1：1的块体金属玻璃的屈服强度几乎与其他长径比的块体金属玻璃的断裂强度接近；另外，本文作者也探讨了铜基块体金属玻璃力学性能对加载速率和长径比的响应机理。