脉冲放电驱动磨料流辅助磨削单晶碳化硅研究  

Study on Impulse-discharge Driven Abrasive Flow Assisted Grinding of Monocrystalline SiC

作　　者：陈钊杰 谢晋[1] 刘军汉[2] 熊长新[2] 李迪帆 CHEN Zhaojie;XIE Jin;LIU Junhan;XIONG Changxin;LI Difan(School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640;Huazhong Institute of Electro-Optics-Wuhan National Laboratory for Optoelectronics,Wuhan 430223)

机构地区：[1]华南理工大学机械与汽车工程学院,广州510640 [2]华中光电技术研究所-武汉光电国家研究中心,武汉430223

出　　处：《机械工程学报》2024年第9期383-392,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51975219,52375493);广东省基础与应用基础研究基金(2022A1515220053)资助项目。

摘　　要：单晶碳化硅作为半导体材料,其被加工表面及亚表面质量直接影响到电、磁、光等工作性能,但在高精度的机械加工中,纳米切深的不可控和高速主轴转动的刀具端跳会产生不稳定的切削力,导致表面微毛刺和改性层以及亚表面残余应力和损伤。因此,在单晶碳化硅的金刚石磨削中,利用砂轮与工件间的脉冲放电驱动游离磨料流动,抵消机械作用对其表面及亚表面的影响,探究机械加工、磨料流抛光和热化学去除的复合加工对表面完整性的作用机制。首先建立复合加工表面成型与脉冲放电和流体动压的关系模型,然后分析脉冲放电对材料去除率以及磨粒损耗率的影响,最后讨论去毛刺效果、表面残余应力及亚表面损伤等。结果表明:在固结磨粒切削与轮廓复制过程中工件与磨粒界面形成了复合加工链,脉冲放电可驱动游离磨粒并对表面进行热化学改性,游离磨粒获得去除力去消除表面二氧化硅并重新暴露出Si-C键。降低脉冲放电能量和流体动压会促进脆性破坏转变为高表面质量的塑性去除。即使较大切深和较大主轴端跳产生的机械振动,脉冲放电驱动的热化学改性及游离磨粒抛光与金刚石磨削复合可以将残余压应力、表面微毛刺和亚表面损伤层厚度分别减少93%、73%和50%。The surface quality of monocrystalline SiC,as a semiconductor material,influences its electrical,magnetic,and optical performance.However,during mechanical processing,the cutting depth and the mechanical runout lead to unstable cutting force,resulting in surface micro-burr,modified layer,subsurface residual stress and damage.Thus,an impulse-discharge between wheel metal and SiC is proposed in diamond grinding to drive a loose-abrasive flow.It aims to investigate the mechanism by which the hybrid effects of mechanical processing,abrasive flow polishing,and thermochemical removal influence surface integrity.The surface formation is first modelled in relation to impulse discharge energy and hydrodynamic pressure.Then,the material removal rate and abrasive wear rate are investigated.Finally,the surface integrity is investigated.It is shown that the hybrid machined formation chain was formed in the abrasive-workpiece interface.The impulse-discharge drove the loose-abrasive and modified the interface by thermochemical modification.The loose-abrasive obtained a removal force to eliminate the modified SiO2 and expose the SiC substrate.Decreasing the impulse-discharge energy and hydrodynamic pressure promoted brittle removal to ductile removal.Under the mechanical vibrations generated by large cutting depths and spindle runout,the hybrid machining of impulse-discharge driven thermochemical modification and loose-abrasive polishing,in conjunction with diamond grinding,could effectively reduce residual compressive stress,surface micro-burrs,and subsurface damage layer thickness by 93%,73%,and 50%,respectively.

关 键 词：亚表面损伤 残余应力 单晶碳化硅 脉冲放电 磨料流加工 

分 类 号：TN305[电子电信—物理电子学]