多线切割保公差工艺对烧结钕铁硼永磁体表面质量的影响

Influence of multi wire cutting tolerance maintaining process on the surface quality of Nd-Fe-B magnets

采用多线切割保公差工艺切割烧结钕铁硼永磁体,利用SJ-410粗糙度仪、JMS-6010LA型扫描电子显微镜对微观形貌及表面粗糙度R_(a)进行表征。结果表明:随着进给速度增高和线速度的降低,金刚石磨粒压入深度减小,微观形貌由深犁沟、凹坑、破损变为浅犁沟、浅凹坑和破碎,材料去除机理由塑性去除变为塑性变形。粗糙度R_(a)随着进给速度和线速度的增高而减小;进给速度和线速度对法向载荷呈相反作用,在不同工艺参数下的材料去除方式中,塑性变形和塑性去除占据主导作用,进给速度10 mm/h和线速度1190 m/min的粗糙度最低,表面质量最优。切割时间只与进给速度有关,线弓随着进给速度增加,随线速度降低。

The Nd-Fe-B magnet was cut by Multi wire Cutting Process of Tolerance Maintaining,the micromorphology and surface roughness R_(a) were characterized by SJ-410 roughness meter and JMS-6010LA scanning electron microscope.The results show that with the increase of feed speed and the decrease of linear speed,the indentation depth of diamond grains decreases,and the micro-morphology changes from deep grooves,pits and damage to shallow grooves,shallow pits and crushing,and the material removal mechanism changes from plastic removal to plastic deformation.The roughness R_(a) decreases with the increase of feed speed and linear speed,and the feed speed and linear speed have opposite effects on the normal load.Plastic deformation and plastic removal play a dominant role in the material removal methods under different process parameters,and the roughness of feed speed 10 mm/h and linear speed 1190 m/min is the lowest and the surface quality is the best.The cutting time is only related to the feed speed,the line bow increases with the feed speed and decreases with the line speed.