预应力砂带磨削钛合金表面完整性的试验研究

摘要

为了提高钛合金加工表面的抗疲劳性和抗腐蚀性,基于预应力砂带磨削原理,进行不同预应力条件(0、100 MPa和200 MPa)下的钛合金砂带磨削试验.通过检测、分析不同预应力条件下磨削后工件的表面完整性,获得不同预应力对工件表面残余应力、粗糙度、硬度及表面形貌的影响规律;并在砂带磨粒模型的基础上,揭示预应力砂带磨削对残余应力和表面形貌的作用机理.结果表明:在材料的弹性范围内施加预应力并进行磨削能够主动加强工件表面的残余压应力状态;随着预应力的增加,残余压应力的大小呈现逐渐递增的趋势;预应力砂带磨削对表面硬度的影响甚小,且在一定范围内不随预应力的变化而变化;采用预应力砂带磨削能够得到较好的表面形貌,但会使粗糙度有微量增加.%In order to improve the fatigue resistance and corrosion resistance of titanium alloy,the tests of abrasive belt grinding of titanium alloy are conducted on different prestressed conditions(0,100 MPa and 200 MPa)based on the principle of prestressed abrasive belt grinding.On different prestressed conditions,the influence rules of the residual stress,surface roughness,hardness and surface topography of the workpiece are obtained by testing and analyzing the surface integrity of the workpiece.Based on the model of abrasive belt grain,the mechanisms that prestressed abrasive belt grinding affects the residual stress and surface topography are revealed.The research shows that,within the elastic deformation limit of titanium alloy,the condition of compressive residual stress on surface of workpiece can be actively strengthened by applying prestress.The larger the magnitude of prestress is,the larger the compressive residual stress.The influence of prestressed abrasive belt grinding on the surface hardness is insignificant,and the surface hardness does not change with prestress.The workpiece machined by prestressed abrasive belt grinding can obtain good surface topography but there is slight increase in roughness.