超精密车削单晶硅刀具振动频谱分析

Tool Vibration Spectrum Analysis in Ultra Precision Diamond Turning of Single Crystal Silicon

为了在线监测单晶硅超精密车削的脆塑转变现象及分析单晶硅车削过程中材料的微纳去除方式,采用圆弧刃金刚石刀具对单晶硅(100)晶面进行了超精密车削,研究了单晶硅超精密车削时刀具振动频谱分布与切削参数的关系,并对刀具振动频谱的变化规律及其演变机理进行了分析.结果表明,刀具振动频谱分布与刀具和单晶硅接触方式、单晶硅微纳去除模式密切相关.当单晶硅的去除模式从脆性域过渡到塑性域时,材料由崩碎状脆性去除方式转变为以剪切滑移变形为主的塑性去除方式,刀具振动频谱高频段信号增多,且振动总能量增大;塑性域车削时,切削速度越小、切削深度越大、进给量越大,材料微观剪切变形区内位错滑移数量越多,刀具振动频谱高频段信号越多,刀具振动主总能量越大.切削速度、进给量、切削深度对刀具振动频谱分布的影响依次减小,采用合理的切削参数,可以降低切削系统的总体振动.

In order to monitor the brittle-ductile transition in diamond turning of single crystal silicon online and analyze the micro-deformation removal mode of the material,a series of experiments were carried out on the crystalline plane（100） of single crystal silicon with a rounded diamond cutting tool,and the relationship between the distribution of tool vibration spectrum and the cutting parameters was investigated in this paper,especially the variation rule of the tool vibration spectrum and mechanism of brittle-ductile transition.Experimental results indicate that the distribution of tool vibration spectrum is dependent on the contact mode between tool and silicon wafer,and the micro/nano removal mode of single crystal silicon.With the transition of single crystal silicon removal mode from brittle regime to ductile regime,the material removal mode transforms from the brittle fracture mode to plastic deformation characterized with shearing slide,and high frequency signals in the tool vibration spectrum and total energy of vibration both increase.Moreover,lower cutting velocity,greater cutting depth and larger feed rate will lead to more high frequency signals in the tool vibration spectrum and greater total energy of vibration in ductile regime cutting,because the dislocation can be carried out sufficiently in the micro shearing deformation zone of the material.Furthermore,the effects of cutting velocity,feed rate and cutting depth on the distribution of tool vibration spectrum decrease in turn,so that the application of reasonable cutting parameters can reduce the overall vibration of the cutting system.