Effects of temperature, punch angle, and loading velocity on mechanical properties of nanoimprinted FeNiCoCrCux high-entropy alloys

Abstract

In this work, we use molecular dynamics simulations to study the effects of temperature, loading velocity, the taper angle of the punch on mechanical characteristics and deformation behavior of FeNiCoCrCu high-entropy alloys (HEAs) in nanoimprinting process. The impact of these factors is evaluated through loading force, atomic shear strain, structural change, dislocation evolution and elastic recovery rate. It points out that the primary deformation mechanism during imprinting of FeNiCoCrCu HEAs materials is the occurrence and propagation of dislocation and stacking faults. Increasing the temperature reduces the loading force, and the nanopatterning ability is better. When the imprinting speed increases, the stacking fault and dislocation increase, and the loading force improves. The results show that the higher the imprinting speed, the smaller the elastic recovery ratio. That proves the pattern forming at high imprinting speed will be better. As the mold angle increases, the depth of the forming groove increases. With the change of mold angles, the stress changes not only its value but also its distribution. As the taper angle of the punch increases, the high-stress region increases. The lower the concentration of Cu in the compound, the higher the forming ability and the pattern is sharper and clearer. While, the total dislocation and the residual stress in the substrate after withdrawing the punch from the substrate will gradually decrease on the order of FeNiCoCrCu0.2, FeNiCoCrCu1.3, FeNiCoCrCu0.7, FeNiCoCrCu0.4, FeNiCoCrCu1.0.