The influences of chemical disorder and external loading conditions on the reversible structural transformation between hexagonal close-packed (HCP) and face centred cubic (FCC) phases in CrCoFeNi high entropy alloys (HEAs) are studied from first-principles calculations. The generalised planar fault energy curves are utilised to analyse the competition between the transformation and deformation twining in the HEA. It is found that the transformation-induced plasticity (TRIP) could occur in CrCoFeNi HEA through the reversible HCP-to-FCC transformation under hydrostatic pressures or uniaxial tensions, which is enhanced in the regions with high or low local concentration of Co or Ni, respectively. These findings well explain on the TRIP in CrCoFeNi HEAs from an energetics perspective, and provide useful information on the effects of chemical disorder on dislocation activities in HEAs. The results reported in this work could facilitate the development of HEAs with structural transformation accommodated plasticity.

通过第一性原理计算，研究了化学无序和外部加载条件对CrCoFeNi高熵合金（HEA）中六方密堆积（HCP）相和面心立方（FCC）相之间可逆结构转变的影响。利用广义平面断层能量曲线分析了HEA中变形和孪生孪生之间的竞争。研究发现，在静水压力或单轴张力下，可逆HCP-FCC相变可在CrCoFeNi HEA中发生相变诱导可塑性（TRIP），在局部或局部Co或Ni浓度高或低的区域，相变诱导可塑性会增强。分别。这些发现从能量学角度很好地解释了CrCoFeNi HEA中的TRIP，并提供有关化学异常对HEA中位错活动影响的有用信息。这项工作报告的结果可以通过结构转换适应可塑性促进HEA的发展。