金刚石飞切加工微结构表面的工艺参数优化

摘要

In order to obtain micro-structured surfaces with nano-surface finish,a three-dimensional diamond fly-cutting system was established based on a ' Nanosys-300' ultra-precision machining system.The effects of the spindle speed,feed rate,as well as the cut depth on the roughness were investigated,respectively.The analytical result of Theoretic Surface Roughness (TSR) shows that the TSR is a constant along the normal direction,while TSR is a periodic variety along the feed direction.The TSR is reduced with the decreases of feed rate and nose angle of a tool or the increase of cutting radius.The experimental results reveal that roughness R_s is reduced with the decreases of feed rate and cut depth on Polycarbonate( PC),while it is increased with the decrease cut depth or the increase of feed rate on aluminium(LY12).However,the spindle speed have not a significant impact on R_a for both materials.The roughness of 38 nm on LY12 and 43 nm on PC are achieved.Finally,a micro pyramid array and a V-groove array are processed with the pointed V-shaped single crystal diamond tool on aluminum alloy LY12 successfully.%为了获得具有纳米级表面质量的微结构表面,利用‘Nanosys-300'超精密复合加工系统实现了微结构表面的三维金刚石飞切加工,研究了主轴转速、进给量以及背吃刀量对微结构表面粗糙度的影响.理论分析表明,金刚石飞切加工微结构时理论表面粗糙度沿法线方向并没有变化,而沿进给方向存在着周期变化.减小进给量和金刚石飞刀前端角或增大切削半径可以降低理论粗糙度值.实验分析表明,表面粗糙度值Ra随进给量的增加而增加,主轴转速对Ra影响不大.切削聚碳酸酯(PC)时,在5～40 μm Ra随背吃刀量的增加而增加;而切削铝合金(LY12)时,在2～10 μm Ra随背吃刀量的增加而减小.实验中Ra最好可达38 nm(LY12)和43 nm(PC).最后,利用优化工艺参数加工出了微沟槽阵列和微金字塔矩阵微结构.