高温合金短电弧辅助铣削表面完整性演化研究  

Research on Surface Integrity Evolution of Short Arc Assisted Milling of Superalloy

作　　者：王湃 白翌帆 赵文祥[1] 张毅博 刘志兵[1] WANG Pai;BAI Yifan;ZHAO Wenxiang;ZHANG Yibo;LIU Zhibing(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081;Beijing Institute of Computer Technology and Applications,Beijing 100854;Beijing Power Machinery Institute,Beijing 100074)

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]北京计算机技术及应用研究所,北京100854 [3]北京动力机械研究所,北京100074

出　　处：《机械工程学报》2024年第9期434-444,共11页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(52075042)。

摘　　要：短电弧铣削加工技术因低加工应力、低成本、高加工效率而被应用在镍基高温合金加工中。针对短电弧辅助精密铣削加工表面完整性演化规律不明的问题,利用扫描电子显微镜(SEM)、能量色散X射线谱(EDS)等检测手段分析了重铸层的组织特性,开展正交铣削试验研究了精密铣削工艺参数对表面完整性的影响规律以及重铸层导致的铣削表面差异,探究了短电弧辅助精密铣削表面强化机制。结果表明,高温合金晶体在高温下破坏重组导致其组织变化形成重铸层,硬度降低34%,脆性增强;相同参数下短电弧辅助铣削表面表现出更高的粗糙度值(Ra=0.76μm)、更高的表面硬化率(47.8%)与更大的残余拉应力值(沿进给方向(X向)为241.5 MPa,垂直进给方向(Y向)为78 MPa)。加工表面硬化的主要机制是位错强化,通过引入核心平均取向差参数建立的显微硬度预测模型进一步拓展了表面完整性与晶体学特征的关系。Short arc milling technology is applied to nickel-based superalloy processing due to low machining stress,low cost and high machining efficiency.Aiming at the problem that the evolution law of surface integrity in short arc assisted precision milling is unclear,the microstructure characteristics of the recast layer are analyzed by means of scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and other detection methods.The influence of precision milling process parameters on surface integrity and the difference of milling surface caused by the presence of recast layer are studied by orthogonal milling experiments.The surface strengthening mechanism of short arc assisted precision milling is clarified.The results show that the destruction and recombination of the superalloy crystal at high temperature leads to its microstructure change to form a recast layer,the hardness is reduced by 34%,and the brittleness is enhanced.Under the same parameters,the surface of short arc assisted milling shows higher roughness(Ra=0.76μm),higher surface hardening rate(47.8%),and larger tensile residual stress(along the feed direction(X direction)is 241.5 MPa,and in the vertical feed direction(Y direction)is 78 MPa).Dislocation strengthening is the main mechanism of machined surface hardening.The microhardness prediction model established by introducing the kernel average misorientation parameter further expands the relationship between surface integrity and crystallographic characteristics.

关 键 词：短电弧 重铸层 表面完整性 显微硬度 表面强化 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]