中文摘要：

针对高硬度金属基微结构镶块的加工,提出一种6工位组合电极电火花成形的新方法。以聚合物微流控芯片模具型腔镶块为研究对象,选用NAK80模具钢为镶块材料、铜钨合金（70%w）为电极材料,依据镶块上十字交叉的微凸起结构以及电火花成形电极的损耗规律,设计6工位窄缝组合电极。通过多次切割、恒速进给的工艺手段,利用精密慢走丝线切割加工出该组合电极,窄缝直角拐角处形状误差小于5μm、窄缝宽度误差在±2μm左右。利用此组合电极,以变换加工工位代替传统的更换电极工艺,在补偿电极损耗的同时避免引入重复定位误差,通过精密电火花成形,依次完成粗、半精与精加工,成形出微凸起结构镶块。微凸起截面近似梯形,表面粗糙度Ra0.208μm,可以满足聚合物微流控芯片成形的基本要求。

英文摘要：

In accordance with the manufacturing of microstructure mold insert with high hardness, a kind of electrical discharge machining method by use of a six-station combination electrode is proposed. The mold insert for micro fluidic chip molding is selected as researched object, NAK80 as the material of mold insert, and copper-tungsten alloy （70%w） as the material of the electrode. The combination electrode with six narrow slits is designed according to the raised micro cross structure of the mold insert and the wear law of electrode during electrical discharge machining. The combination electrode is machined by precision wire-cut electrical discharge machining, using multiple cutting and constant feeding. The error of comer shape on the narrow slit is less than 5 pro; the width tolerance is about ~2 gin. Instead of changing electrodes traditionally, the method of transforming the electrode station is applied; the repeatability of positioning error can be avoided. The raised micro cross structure is formed by precision EDM with the combination electrode, followed by completion of the rough, semi-finishing and finish machining. The cross section of the microstructure is approximately trapezoid, and the surface roughness of the mold insert is Ra 0.208 grn, all this can be satisfied with the primary demand of micro fluidic chip molding.