【摘要】 在Ti-6Al-4V切削加工过程中存在热-力耦合作用，由此产生的局部高温、高应力和剧烈塑性变形会诱发动态再结晶，导致合金表层晶粒发生细化，从而影响合金加工后的力学性能。为探究切削参数对晶粒细化的影响，进行切削试验，分析切削表层的微观结构特性及物相变化情况，并根据基于位错理论所建的晶粒细化模型，利用Fortran语言将其编写成子程序，对有限元分析软件(ABAQUS)进行二次开发，实现Ti-6Al-4V切削中的晶粒细化仿真。结果表明：仿真后的切削表层产生晶粒细化，细化效果随切削速度增加而降低，且晶粒尺寸由表及里逐渐减小，与试验结果一致；原有α相和β相衍射峰强度随切削速度增加而增加，且生成新的氧化物相，使晶粒细化效果减弱。更多还原

【Abstract】 During the cutting process of Ti-6Al-4V,the local high temperature, high stress and intense plastic deformation induced by the thermo-mechanical coupling effect can trigger dynamic recrystallization, resulting in grain refinement on the surface of the alloys and thus the change in mechanical properties of the alloys after processing.To investigate the influence of cutting parameters on grain refinement, cutting experiments were conducted.The microstructural characteristics and phase evolution of the cutting surface layer were analyzed.Based on the grain refinement model established by dislocation theory, a subroutine was written by Fortran and the finite element analysis software(ABAQUS) was secondarily developed to realize the grain refinement simulation in the cutting of Ti-6Al-4V.The results show that after simulation, the cutting surface layer exhibits grain refinement.The refinement effect becomes stronger as the cutting speed increases, and the grain size gradually decreases from the surface to the interior, which is consistent with the experimental results.With increasing the cutting speed, the intensities of the original α-phase and β-phase diffraction peaks are both enhanced; Whilst the formation of new formed oxide phase results in the weakening of the grain refinement effect.更多还原