镍基合金螺旋铣孔加工质量研究
2019-01-16
作者：王超，赵军，周咏辉
单位：山东大学机械工程学院高效洁净机械制造教育部重点实验室；机械工程国家级实验教学示范中心(山东大学)
摘要：进行了GH4169镍基合金螺旋铣孔加工的正交试验及后续检测，研究了加工质量（尺寸精度、表面质量），并以此探究采用螺旋铣孔工艺替代常规钻孔加工镍基高温合金的可行性。试验及检测结果表明：螺旋铣孔工艺制孔的入口质量良好，无毛刺，但出口处质量稍差，出现了较明显的毛刺；在合理的参数选取范围内，制孔的孔径偏差和圆度偏差能够满足航空工业的要求；孔壁最大表面粗糙度Ra为0.345μm，远低于常规钻孔的孔壁表面粗糙度，达到了精加工的水平；孔壁表面层出现了一定程度的加工硬化（硬化程度为118.8%-125.1%），但并没有出现热软化现象；孔壁表面残余应力表现为压应力（应力范围-902.0MPa~-396.3MPa），有利于提高孔的疲劳寿命。因此，螺旋铣孔工艺能够提高镍基高温合金制孔的加工质量，在加工镍基合金时替代常规钻孔工艺是可行的。
关键词：螺旋铣孔；镍基高温合金；加工质量
中图分类号：TG713；TH161.1文献标志码：ADOI：10.3969/j.issn.1000-7008.2019.01.010
Study on Machining Quality of Helical Milling for Nickelbased Superalloy
Wang Chao，Zhao Jun，Zhou Yonghui
Abstract:Through a series of orthogonal experiments in the helical milling process of GH4169 nickelbased superalloy and some subsequent testing，the machining quality(dimensional quality and surface quality)of helical milling is studied and the feasibility of replacing conventional drilling with helical milling when machining nickelbased superalloy is investigated.The results revealed that the machining quality of hole entry is good without any burr，but the machining quality of hole exit is slightly poor with obvious burrs，the dimensional deviation and roundness deviation of hole can meet the requirement in aerospace industry in the range of reasonable parameters，the maximum surface roughness of hole Ra is 0345μm，which is much lower than that of hole made by conventional drilling，and reached the level of finishing，the surface layer of hole has a certain degree of workhardening with hardening capability of 118.8%～125.1%，but no heat softening phenomenon occurs，the compressive residual stress (about -902.0MPa～-396.3MPa)can improve the fatigue life.In conclusion，the helical milling technology can improve the machining quality of hole for nickelbased superalloy，and it is fesible to replace conventional drilling with helical milling while machining nickelbased superalloy.
Keywords:helical milling；nickelbased superalloy；machining quality