单晶镍基高温合金DD98微铣削表面质量试验

为研究单晶高温合金的微铣削表面质量,使用M.A.FORD双刃端铣刀,刀刃直径为0.8 mm,试验材料为单晶高温合金DD98,完成正交试验研究.通过极差分析找出主轴转速、进给速度、铣削深度对微铣削表面质量影响的主次因素,即主轴转速的影响最大,铣削深度其次,进给速度最小;采用统计学知识,获得切削工艺参数的优化组合,使表面粗糙度最小,即主轴转速为n=3.6 kr/min,铣削深度为ap=5μm,进给速度为v=100μm/s,对此优化方案重复试验,表面粗糙度值为951 nm.并对其切削机理和影响表面质量及形貌的原因进行深入的分析,对单晶高温合金的微加工理论的机理揭示具有一定的指导意义.

Experiment on Surface Quality in Micro-milling of Single Crystal Ni-Based Superalloy DD98

To study the micro-milling surface quality of single crystal superalloy， orthogonal experiment was implemented for micro-milling of single crystal Ni-based superalloy DD98 by using the M.A.FORD two-edged micro-milling tool with 0.8mm diameter. The primary and secondary impacting factors on the micro-milling surface quality， such as spindle speed， feed rate and milling depth were analyzed by range analysis. The results show that the influence of spindle speed is the greatest， the milling depth is the secondary， while the feed rate is the smallest. Using statistical theory， the ideal cutting process parameters was optimized and obtained， i.e， 3.6kr/min speed spindle， 5μm milling depth and 100μm/s feed rate. The surface roughness is minimum under the above combination condition. The experiments were repeatedly done with the optimized scheme to get a surface roughness (R_a) of 951nm. The cutting mechanism， the reasons of affecting surface quality and morphology were further analyzed. The experiment result may provide some reference for micro-milling mechanism of single crystal superalloy.