结构弛豫对Zr_(64.13)Cu_(15.75)Ni_(10.12)Al_(10)块体非晶合金硬度和剪切带特征的影响

Effect of Structural Relaxation on Hardness and Shear Band Features of Zr_(64.13)Cu_(15.75)Ni_(10.12)Al_(10) Bulk Metallic Glass During Indentation

通过接近玻璃转变温度的等温退火获得不同弛豫状态的Zr64.13Cu15.75Ni10.12Al10块体非晶合金样品。利用维氏显微硬度计和洛氏硬度计研究结构弛豫对合金硬度和压痕周围剪切带特征的影响规律。结果表明:在590K等温退火处理使Zr64.13Cu15.75Ni10.12Al10块体非晶合金发生焓弛豫行为,其维氏显微硬度随退火时间的延长较快增加后趋于稳定,而大载荷洛氏硬度对结构弛豫不敏感。通过洛氏压痕周围剪切带特征的研究,定量比较了结构弛豫对剪切带间距、数量的影响规律。

Structural relaxation of Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass （BMG） was conducted through isothermal annealing at the temperature near glass transition. Vickers hardness and Rockwell hardness tests were used to study the structure relaxation effect on the hardness and shear band features of the BMG. The results show that Zr64.13Cu15.75Ni10.12Al10 BMG underwent enthalpy relaxation due to pre-annealing at 590 K. Vickers hardness increases quickly upon pre-annealing and tends to grow slowly with further increasing the pre-annealing time. In contrast, the Rockwell hardness of the BMG is insensitive to the pre-annealing time. Well developed shear band pattern is also found around the Rockwell indents after indentation. The shear band number and spacing are correlated quantitatively with the pre-annealing time.