多工位组合电极电火花成形微凹槽结构  

Micro groove structure with multi-station combination electrode by EDM

作　　者：宋满仓[1,2] 李文明[1,2] 刘莹[1] 刘冲[1] 

机构地区：[1]大连理工大学精密与特种加工教育部重点实验室,辽宁大连116024 [2]三菱电机大连理工大学电加工技术中心,辽宁大连116024

出　　处：《光学精密工程》2015年第12期3371-3377,共7页Optics and Precision Engineering

基　　金：国家863高技术研究发展计划资助项目(No.2012AA040406);中央高校基本科研业务费专项资金资助项目(No.DUT13JB05);辽宁省自然科学基金资助项目(No.201202036)

摘　　要：针对具有复杂微尺度凹槽结构的高硬度模具钢型腔难以加工的难题,提出了一种多工位组合电极电火花成形的新方法。以某种聚合物微流控芯片模具型腔为研究对象,选用NAK80模具钢为型腔材料,铜钨合金(W75%)为相应的微凸起结构电极材料并经由高速铣削加工。为降低加工难度及保障加工质量,对复杂微凸起结构进行分解,形成2组4工位组合电极;采用周铣、端铣交替进行的工艺使微凸起上表面的毛刺连续发生塑性变形从而减小和去除微凸起结构顶端的加工毛刺。最后,利用制备好的多工位组合电极,采用变换工位代替更换电极的加工方式,通过精密电火花成形,依次完成粗、半精与精加工。结果表明:加工的凹槽侧壁与底面垂直度较好,宽度、高度误差在3μm以内,根部圆角在15μm以内,可以满足成型聚合物微流控芯片的使用要求。As a complex micro groove cavity made of mold steel with high hardness is difficult to be machined,a kind of electrical discharge machining method by use of a multi-station combination electrode is proposed.The cavity for micro fluidic chip molding is selected as researched object,NAK80 as the cavity material,and copper-tungsten alloy（75%W）as the material of the corresponding electrode with a micro convex structure manufactured by High Speed Milling（HSM）.To reduce processing difficulty and ensure processing quality,the complex micro convex structure is decomposed into two groups of four-station combination electrodes.By alternating peripheral milling and end milling,the surface of the micro convex structure generates continuous plastic deformation,which reduces and removes the top processing burr of the micro convex structure and the burr can be reduced and re-moved.Finally,based on the qualified multi-station combination electrode,the rough,semi-finishing and finish machinings are completed successively by using precision Electrical Discharge Machining（EDM）and transforming the electrode station instead of changing electrodes.Experimental results show that the verticality of the groove sidewall is good enough,the height and width errors are within3μm,the root radius is within 15μm,and all this satisfies the demand of micro fluidic chip molding.

关 键 词：微凹槽结构 微尺度型腔 多工位组合电极 高速铣削 去毛刺 电火花成形 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]