机电工程学院知识库

The nano-cutting and tensile model of monocrystalline γ-TiAl alloy was established by large scale molecular dynamics simulations method. The effect of different cutting depths on tensile process of workpiece was analyzed. For one thing, the relationship between lattice transformation and micro-defect evolution was studied. For another, the influences of cutting depths on stress-strain curve, the nucleation of dislocation and position of fracture surface were discussed. The results show that the amount of lattice transition rises with the increases of cutting depth and it is consistent with micro-defect evolution during nano-cutting. Within a certain range of cutting depth, the yield stress and elastic modulus of workpiece are improved correspondingly. In addition, cutting depths have great influence on the position of dislocation nucleation and fracture surface of workpiece during tensile process. The dislocation of machined workpiece is nucleated at subsurface, while dislocation of unmachined workpiece is nucleated at edge of workpiece. The port position of workpiece is closer to drawing end with the increase of cutting depth. Copyright © 2020, Northwest Institute for Nonferrous Metal Research. Published by Science Press. All rights reserved.