Hf-基非晶合金的力学性能研究

 利用MTS810实验机和分离式霍普金森压杆（SHPB），对Hf_44.5Cu₂₇Ni_13.5Ti₅Al₁₀块体非晶合金进行了准静态和动态压缩实验，应变速率范围为10^-4~10³ s^-1，给出了不同应变速率下非晶合金的应力-应变曲线，并对其压缩断口形貌进行了扫描电镜观察。结果表明：在准静态压缩条件下，Hf_44.5Cu₂₇Ni_13.5Ti₅Al₁₀非晶合金不具有应变速率敏感性，在由放射区和扇形区组成的断口形貌上观察到纳米级韧窝和60 nm左右的周期性条纹结构；在动态压缩条件下,随着应变速率的增加，动态屈服强度明显减小，合金具有应变速率敏感性，同时断裂表面为夹杂着脉络条纹的絮状结构。进一步观察发现，动态压缩断口上存在3种特征断裂形貌：树枝状条纹、典型脉络花纹和合金熔体。

Mechanical Properties of Hf-Based Metallic Glasses

The quasi-static and dynamic compression tests for Hf44.5Cu27Ni13.5Ti5Al10 metallic glass were done by MTS810 and split Hopkinson pressure bar(SHPB) in the range of strain rate of 10-4-103 s-1.The compressive stress-strain curves were obtained under varied strain rate and the fracture morphologies were studied by scanning electron microscopy.The experimental results show that the Hf44.5Cu27Ni13.5Ti5Al10 metallic glsaa does not have the strain rate sensitivity under quasi-static compression.The dimple structure and periodic corrugations with about 60 nm spacing can be observed at the fracture surfaces which consist of radical zone and fan-shaped zone.Under dynamic compression,the yield strength rapidly declines with rise of strain rate,the metallic glass has the strain rate sensitivity.The fracture surfaces show floccule structure with vein-like patterns.Further observation reveals that dynamic compression fracture surfaces exist three fracture morphology:branch-like patterns,vein-like patterns and molten agglomerates.