镍基单晶高温合金磨削润滑方式对表面完整性的影响

Influence of grinding lubrication methods on surface integrity of nickel-based single crystal superalloy

为提高镍基单晶高温合金DD5的磨削表面质量,采用单因素试验探究3种磨削加工方法(干磨削、传统浇注式、微量润滑(minimum quantity lubrication,MQL))对其表面完整性的影响。结果表明:在不同冷却条件下,DD5磨削表面粗糙度从低到高依次为MQL、传统浇注式、干磨削方式下的。当砂轮线速度较小时,磨削表面质量较差,存在较深划痕和沟槽;当砂轮线速度较大时,磨削表面质量较好,磨痕较小,且分布均匀。在距磨削表面为5~15μm时,DD5亚表面显微硬度随着深度的增加而急剧下降;在距磨削表面为20~150μm时,DD5亚表面显微硬度趋于平衡,其在540 HV附近波动。

To improve the grinding surface quality of nickel-based single crystal superalloy DD5,the influence of three grinding methods(dry,conventional flood,minimal quantity lubrication)on their surface integrity was investigated us-ing single factor experiment.The results show that under different cooling conditions,the grinding surface roughness of nickel-based single crystal superalloy DD5 is MQL,conventional flood and dry grinding from low to high.When the linear speed of the grinding wheel is small,the grinding surface quality is poor,and there are deep scratches and grooves;when the linear speed of the grinding wheel is large,the grinding surface quality is good,the grinding marks are small and evenly distributed.When the depth from the grinding surface is 5~15μm,the subsurface microhardness of DD5 decreases sharply with the increase of depth.When the depth from the grinding surface is 20~150μm,the subsur-face microhardness of DD5 tends to balance and fluctuates around 540 HV.