In this investigation synergistic assessments of fracture toughness and activation volume for plastic deformation of two typical body centered crystalline (bcc) and face centered crystalline (fcc) high entropy alloys containing Al, Cr, Co, Cu, Fe and Ni have been made by standard practices; these experiments together with the assessment of conventional mechanical properties were carried out to understand the underlying mechanisms responsible for the deformation and fracture response of high entropy alloys. The estimations of the mechanical properties are supplemented by micro- and sub-structural examinations using optical, scanning and electron microscopy as well as X-ray diffraction analyses. The major results indicate that the bcc alloy exhibits higher hardness and strength with inferior fracture toughness compared to the fcc alloy. This characteristic observation has been explained with the nature of the constituent phases in the two alloys, the magnitudes of the activation volume which dictate the underlying deformation mechanisms and some limited qualitative signatures of the dislocation characteristics. The exploration and the understanding of the underlying mechanisms for deformation and fracture would assist the technologists to evaluate the potential of high entropy alloys for structural applications.

在这项研究中，已通过标准对含铝，铬，钴，铜，铁和镍的两种典型的体心结晶（bcc）和面心结晶（fcc）高熵合金的断裂韧性和塑性变形的活化量进行了协同评估。做法；通过进行这些实验以及对常规机械性能的评估，以了解引起高熵合金变形和断裂响应的潜在机理。通过光学，扫描和电子显微镜以及X射线衍射分析对微观和亚结构进行检查，可以补充对机械性能的估计。主要结果表明，与fcc合金相比，bcc合金具有较高的硬度和强度，而断裂韧性较差。已经用两种合金中组成相的性质，激活体积的大小（决定了潜在的变形机理）和位错特征的一些有限的定性特征来解释了这种特征性观察。对变形和断裂的潜在机理的探索和理解将有助于技术人员评估高熵合金在结构应用中的潜力。