GH4169材料磨削后数控抛光表面完整性试验研究

Research on Surface Integrity for GH4169 of CNC Polishing After Grinding

针对航空发动机叶片材料GH4169高温合金，采用CBN砂轮唐削后进行羊毛毡轮数控抛光首先．研究了抛光预压量对抛光轮寿命和工件表面粗糙度的影响，找到了抛光轮寿命的评价方法和优化的预压量；然后，研究了抛光深度对磨削后GH4169表面完整性的影响，结果表明：表面粗糙度尺。随抛光深度的增加先减小后稳定，表面显微硬度Hv随抛光深度的增加呈显著下降趋势，进给方向表面残余正应力随深度增加先升高后下降，而垂直进给方向表面残余正应力先基本不变后下降最终试验优选出了深度参数为2μm，预压量0．5～1．0mm采用羊毛毡轮对GH4169磨削表面进行抛光，既能达到较小的表面粗糙度值（Ra=0．3gm），又可以有效维持CBN砂轮磨削形成的两个方向较大的表面残余应力。

For the blade material GH4169, the process of CNC polishing after CBN wheel grinding was conducted. Firstly, the influence of the pre-compression parameter on life of wool wheel and the roughness were studied. The influ-ences of polishing depth on the surface topographic characters of surface integrity including surface roughness, surface micro-hardness, and surface residual stress, were studied to optimize the polishing depth. With the increasing of the polish- ing depth, the roughness R, drops firstly and then gets stable, and the surface micro-hardness decreases. The normal residual stress in the feed direction shows a trend from rise to decline, while in the vertical feed direction, it stays unchanged basi- cally and then decreases. The polishing depth after optimized is 21am, and pre-compression parameter is about from 0.5ram to 1.0mm. It has a small roughness of 0.3μm, a macro-hardness of HV389.36 and the high compressive stresses after CBN grinding, which are -871.6MPa and -1084.0MPa for two principal stress directions.