金属陶瓷的干式放电磨削表面粗糙度预测模型  

Prediction Model of Surface Roughness in Dry Electrical Discharge Grinding of Metal Ceramics

作　　者：鲁艳军 孙佳劲 伍晓宇[1] 关伟锋 莫睿 牛立群 LU Yanjun;SUN Jiajing;WU Xiaoyu;GUAN Weifeng;MO Rui;NIU Liqun(College of Mechatronics and Control Engineering,Shenzhen University,Shenzhen 518060)

机构地区：[1]深圳大学机电与控制工程学院,深圳518060

出　　处：《机械工程学报》2022年第11期308-320,共13页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51805334);深圳市国际科技合作(GJHZ20190822091805371);广东省科技计划(2016A040403043)资助项目。

摘　　要：金属陶瓷兼具金属和陶瓷的耐高温、耐腐蚀等优良特性,被应用于各类飞行器外壳、发动机喷口等高端零部件,提出采用环保洁净的干式放电磨削工艺对金属陶瓷进行高效精密加工。研究了金属陶瓷放电磨削过程中单颗磨粒切削深度和放电坑深度与放电磨削工艺参数之间的关系,构建了干式放电磨削工艺参数与磨削表面粗糙度的数学模型,系统研究了砂轮转速、进给速度和磨削深度等磨削工艺参数与开路电压、脉冲宽度和脉冲间隔等脉冲放电工艺参数对金属陶瓷磨削表面质量的影响。结果表明:当磨削深度a_(p)小于磨粒出刃高度h_(g)时,轴向放电磨削表面粗糙度与磨削深度、脉冲间隔等参数无直接关系,随进给速度、开路电压和脉冲宽度的增加而增大,随砂轮转速的增加而减少。与干式放电磨削表面粗糙度的实验测量值相比,建立的数学理论模型能够有效预测其表面粗糙度,预测的最小误差为0.39%,平均误差为6.55%。当开路电压小于30 V(即单颗磨粒切削深度f_(g)大于放电坑有效去除深度h_(c))时,金属陶瓷材料表面去除形式以磨粒机械划擦为主;反之,其材料表面以电火花放电蚀除为主。Metal ceramic has excellent properties both of metal and ceramic including high temperature resistance,corrosion resistance and so on,which is widely used in various types of aircraft shell,engine nozzle and other high-performance components.An environmentally-friendly and clean dry electrical discharge grinding(DEDG)process is proposed to efficiently and precisely machine metal ceramic.The relationships between the cutting depth of single grain and depth of crater and electrical discharge grinding process parameters of metal ceramic are theoretically analyzed.The mathematical model of DEDG process parameters and ground surface roughness is established.The influences of grinding process parameters including wheel speed,feed speed and grinding depth,as well as impulse discharge process parameters including open-circuit voltage,impulse width and impulse interval on the ground surface qualities of metal ceramic are systematically investigated.The results show that when the grinding depth a_(p)was less than the grain protrusion height h_(g),the surface roughness of axial DEDG had no direct relation with grinding depth and impulse interval,but it increased with the increase of feed speed,open-circuit voltage and impulse width,and decreased with the increase of wheel speed.Compared with the measured surface roughness of DEDG,the minimum error and average error of the established mathematical model can reach 0.39%and 6.55%,respectively,which can better predict the electrical discharge ground surface roughness.When the open-circuit voltage is less than 30 V(the cutting depth of single grain f_(g)is greater than effective removal depth of discharge crater h_(c)),the surface removal form of metal ceramic materials was dominated by mechanical grain scratching.On the contrary,the material surface was mainly eroded by electrical spark discharge.

关 键 词：放电磨削 磨削工艺 表面粗糙度 电火花放电 金属陶瓷 

分 类 号：TH16[机械工程—机械制造及自动化]