切削速度对钛合金高速铣削加工表面层相变的影响  

Phase Transformation Influence of Machined Surface Layer in High-speed Milling of Ti-6Al-4V Alloy

作　　者：薛超义 李安海 周咏辉[1,2] 吕明航[1,2] 葛德俊 Xue Chaoyi;Li Anhai;Zhou Yonghui;Lv Minghang;Ge Dejun(School of Mechanical Engineering,Shandong University,Key Laboratory of High Efficiency and Clean Mechanical Manufacture of MOE,Jinan 250061,China;不详)

机构地区：[1]山东大学机械工程学院高效洁净机械制造教育部重点试验室,济南市250061 [2]机械工程国家级试验教学示范中心(山东大学)

出　　处：《工具技术》2021年第11期25-30,共6页Tool Engineering

基　　金：国家自然科学基金(51605260);山东省重点研发计划—重大科技创新工程(2019JZZY010114);山东大学青年学者未来计划(2018WLJH57)。

摘　　要：加工过程中材料的局部相变会直接影响表面完整性的变化。本文研究了Ti-6Al-4V钛合金加工过程中相变与切削参数的关系,通过对Ti-6Al-4V合金进行铣削加工,分析了不同切削速度下铣削力的变化规律。分析了X射线衍射(XRD)图谱和扫描电镜(SEM)图像,研究了铣削参数对加工表面物相比例和塑性变形的影响。结果表明:加工表面发生了相变且XRD图谱中的峰值向右偏移;与基体相比,加工表面的α相比例减小,β相比例增加;在高速切削过程中,切削力、表面硬度和表面残余应力随切削速度的增加而减小,塑性变形层的厚度逐渐增大。在Ti-6Al-4V合金的高速铣削过程中,加工表面层是由热-机械-微观组织耦合作用产生,包括高温软化、强应力和塑性变形以及微观组织相变。Changes in surface integrity are directly affected by the local phase transformations of materials during machining process.This work investigates the relationship between the cutting parameters and phase transformations during machining of titanium alloy Ti-6 Al-4 V.The milling experiments of Ti-6 Al-4 V alloy is conducted,and the variation of milling force under different cutting speeds is analyzed.By observing X-ray diffraction(XRD)patterns and scanning electron microscopy(SEM)images,the effects of milling parameters on the dual-phase ratio and plastic deformation of machined surfaces are studied.The results show that phase transformations occurr on the machined surface and the peak values in the XRD patterns are shifted to the right.Compared with the substrate,theαphase on the machined surface layer decreases,whereas theβphase increases.In high-speed machining process,the cutting force,surface hardness and surface residual stress decrease with the increase of cutting speed.With the increase of cutting speed,the thickness of the plastic deformation layer increases gradually.In high-speed milling of Ti-6 Al-4 V alloy,the machined surface layers are generated by the synergistic interactions among the thermo-mechanical-microstructural effects in terms of the high temperature softening,the intense stress and deformation evolution,the microstructural phase transformation of workpiece material.

关 键 词：钛合金 相变 硬度 残余应力 

分 类 号：TG506[金属学及工艺—金属切削加工及机床] TH161.14[机械工程—机械制造及自动化]