Study On The Influence Mechanism Of Pre-stressing On Surface Roughness In Pre-stressed Hardening Grinding Process

Pre-stressed hardening grinding is a new composite processing technology which combines the Pre-stressed machining with the Grinding hardened.The purpose of grinding is to get a good surface quality and reduce the surface roughness of the components. Therefore, the change mechanism in the surface roughness of prestressed hardening grinding has a very important significance. Compared to ordinary grinding,the influence mechanism of grinding parameters to roughness in Pre-stressed hardening grinding is the same. Therefore, to analyze the distribution characteristics of surface roughness in Pre-stressed hardening grinding, it is essential to analyze the influence of roughness under pre-stressing.This paper has studied the grinding mechanism of Pre-stressed hardening grinding, analysed and calculated the arc contact length, the thickness of undeformation grinding chip and the grinding force in the grinding process.It also focuses on the formation mechanism of the surface roughnessand the relationship between the different grinding parameters and roughness.The paper analyse the influence mechanism of the surface roughness distribution under pre-stessing.It mainly discus the influence of surface residual stress on the roughness after prestressing,also explains the surface roughness effects on resilient deformation caused by pre-stress.To the influence mechanism of roughness caused by residual stress,it mainly analyse the impact of residual stress on dislocation density, grain size and surface micro-cracking.The reason is that residual stress can increase the surface dislocation density and reduce grain size, and also it can inhibit the production of surface micro cracks. In the surface springback deformation due to the prestressing, the pre-stress should be in a reasonable range. With applying prestress, the surface roughness is reduced. But too much of prestress can form folds,so that the surface roughness increases.Based on the theory,the paper uses Deform-3D software for the simulation of Pre-stressed hardening grinding process.It also has received the relationship between grinding force and pre-stress and distribution of surface residual stress and equivalent strain.The simulation results and theoretical analysis is consistent. The prestress does not change the grinding force.The increase of residual compressive stress and surface equivalent strain indicates The increase of surface dislocation density. The paper has analyzed the groove depth under different pre-stress values and found that pre-stress applied should not be too large,within a certain range,the groove depth is gradually decreased with prestressing and pre-stress can effectively reduce the surface roughness.Finally, the surface roughness experiments of Pre-stressed hardening grinding is explored. Research results within reasonable limits imposed increases prestressed prestressed, part surface roughness decreased. With prestressed surface microcracks gradually reduced.The experiments further determine the accuracy of the simulation.