| Double face grinding is an efficient method of plane grinding,which is often used in the manufacture of precision parts with high flatness and parallelism.In view of the unstable geometric accuracy of the machined plane in double-end grinding powder metallurgical stainless steel and other plastic materials,this paper focuses on the thermal characteristics of double-end grinding powder metallurgical stainless steel workpiece.Most of the heat generated by grinding will be taken away by debris.In the process of double-end grinding of powder metallurgical stainless steel,due to the strong plasticity of powder metallurgical stainless steel,the contact mode of surface grinding can not discharge debris in time,which will lead to excessive temperature in the grinding zone,resulting in uneven temperature distribution on the surface of the workpiece and recovery.Surface geometric accuracy is unstable after normal temperature.Therefore,it is of great engineering significance to study the temperature of powder metallurgical stainless steel grinded by double-end grinding.In this paper,by exploring the variation law of surface deformation,temperature and stress in the contact zone,measures to control the quality of double-end grinding of P/M stainless steel workpiece are sought.The main contents of this paper are as follows:(1)The significance and development of double-end grinding are expounded.The material characteristics of P/M stainless steel and CBN grinding wheel are analyzed.The research significance of grinding temperature of P/M stainless steel in double-end grinding and the research progress of finite element simulation grinding temperature are summarized.(2)Based on the principle of velocity synthesis,the processing speed of double-end grinding is calculated and simulated.Modal analysis of the system is carried out to find out its stable operating speed range.The grinding force of a single abrasive particle is calculated by input energy and material removal,and the total grinding force is calculated by cumulative calculation of the cutting force and friction force of a single abrasive particle.Referring to the thermodynamic theory,the distribution of heat flux on the workpiece surface with radius was studied and obtained.(3)Using ANSYS LS-DYNA module,the influence of grinding parameters such as grinding wheel speed and workpiece speed on the grinding process of powder metallurgical stainless steel was analyzed in detail.Multiphysics module was used to simulate the thermo-mechanical coupling under different grinding conditions,and the transient temperature field and structure field varying with time were obtained.(4)After the experiment,the profile of the workpiece and the scratches on the workpiece surface were analyzed,and the variation of grinding temperature in double-end grinding of powder metallurgical stainless steel was obtained.The results of this study reveal the internal mechanism of grinding temperature distribution in double-end grinding of powder metallurgical stainless steel,which is helpful to establish a perfect process parameter system for double-end grinding of powder metallurgical stainless steel materials,and has certain guiding significance for engineering practice. |
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