以单晶镍基高温合金DD98为研究对象,从单晶高温合金微观组织分析材料去除机理,得出DD98滑移面为密排面{111},滑移向为密排方向〈110〉,克服阻力最小,最易滑移.采用双刃微铣刀对单晶镍基高温合金DD98进行正交试验,通过极差分析比较获得切削参数对微铣削力的影响程度.结果表明,主轴转速的影响最大,进给速度其次,铣削深度最小.通过优化获得理想的切削参数为:主轴转速36 000 r/min,铣削深度5μm,进给速度20μm/s,此时微铣削力最小.并对其原因进行深入分析,为单晶高温合金的微加工理论的机理揭示提供理论参考和试验依据.
Taking the single crystal nickel-based superalloy DD98 as research object,the material removal mechanism of single crystal superalloy was analyzed from its microstructure.The glide plane of DD98 is its close-packed plane {111},while the glide direction is its close-packed direction 110 with minimum resistance force and easy slip.The orthogonal experiment was implemented for micro-milling single crystal nickel-based superalloy DD98 by using two-edged micro-milling tool.The effect of cutting parameters on the micro-milling forces was obtained through range analysis.The result showed that the influence of spindle speed is the greatest,the feed rate is the secondary,and the milling depth is the smallest affecting factor.The ideal cutting parameters were obtained using minimum micro-milling forces,i.e.,with the spindle speed of 36 000 r/min,milling depth of 5 μm and the feed rate of 20 μm/s.The reasons affecting on micro-milling forces were deeply analyzed,and the test results may provide certain theory reference and test basis for understanding the micro-milling mechanism of single crystal superalloy.