镍基高温合金GH4169磨削参数对表面完整性影响

Effects of grinding parameters on surface integrity of GH4169 nickel-based superalloy

研究了用单晶刚玉砂轮磨削镍基高温合金GH4169时,磨削参数对表面完整性中的表面特征(表面粗糙度、表面形貌、表面显微硬度和表面残余应力)的影响,以期优化磨削参数.砂轮速度依次选择15,20,25m/s,磨削深度分别选择50,100,150μm,工件速度分别选择5,10,15m/min.研究结果表明:表面粗糙度对工件速度的变化最敏感,表面显微硬度对砂轮速度变化最敏感,表面残余应力对砂轮速度变化最敏感;同时表明了磨削参数对磨削表面形貌、显微硬度梯度、微观组织、残余应力梯度的影响,揭示了表面完整性中的变质层形成规律.其塑性变形层在5～10μm,显微硬度变化影响层为80～100μm,残余应力影响层厚度为80～200μm,其为磨削镍基高温合金表面完整性控制研究提供相关的实验数据基础.

The influence rules of grinding parameters on the surface topographic characters,including surface roughness,surface topography,surface microhardness and surface residual stresses of the surface integrity,were studied to optimize the grinding parameters when grinding the GH4169 nickel-based superalloy by using single crystal corundum grinding wheel.The wheel speed was selected as 15,20,25 m/s,the grinding depth selected as 50,100,150 μm,and the workpiece speed selected as 5,10,15 m/min.The results show that,the surface roughness is most sensitive to the workpiece speed,the surface microhardness and the surface residual stresses are most sensitive to the wheel speed.And the influence rules of grinding parameters on the surface morphology,the gradient of microhardness,microstructure and the gradient of residual stress were studied,revealing the formation rules of metamorphic layer of the surface integrity.The plastic deformation layer is in range of 5~10 μm,the depth of the microhardness change is 80~100 μm,the residual stress affected layer thickness is 80~200 μm,thus providing relevant experimental data base for research of the surface integrity control in grinding nickel-based superalloy.