水平强制振动光整加工对TC4钛合金表面完整性参数的影响

Influences of Horizontal Forced Vibration Finishing on Surface Integrity Parameters of TC4 Titanium Alloys

为探究水平强制振动光整加工对TC4钛合金试件表面完整性的影响,设计单因素实验分析主要工艺参数对表面粗糙度、显微硬度、表面残余应力、接触角的影响,得到较优工艺参数组合;分析较优参数下试件加工前后表面形貌、显微组织及表面晶格变化。研究结果表明:颗粒直径是影响表面粗糙度、显微硬度及残余应力的主要因素。随着颗粒直径的增大,表面粗糙度下降率先提高后降低,显微硬度和残余压应力增大;随着振幅、频率的增大,表面粗糙度下降率提高,显微硬度和残余压应力增大。加工后试件表面粗糙度Ra、Rq、Rz、Rt、RSm最大下降率分别为65.0%、62.2%、45.2%、42.0%和73.7%;显微硬度从320.8HV 0.1增大至363.9HV 0.1;表面残余压应力从-420.38 MPa变化为-621.25 MPa;表面波峰被去除,表层形成了致密层,晶粒组织得到了细化;衍射峰发生了偏移,并引入了数值更大的残余压应力。

To explore the influences of horizontal forced vibration finishing on the surface integrity of TC4 titanium alloy specimens,a single factor experiment was designed to analyze the effects of main processing parameters on surface roughness,microhardness,surface residual stress and contact angle,a better combination of processing parameters was obtained.The changes of the surface morphology,microstructure and surface lattice of the specimens were analyzed before and after processing under the optimal parameters.The results show that particle diameter is the main factor affecting surface roughness,microhardness and surface residual stress.As the particle diameter becomes larger,the roughness reduction rate increases first and then decreases,and the microhardness and surface residual compressive stress become larger.With the increasing of amplitude and frequency,the decreasing rate of surface roughness,microhardness and surface residual compressive stress increase.The maximum decreasing rate of surface roughness Ra,Rq,Rz,Rt and RSm may reach 65.0%,62.2%,45.2%,42.0%and 73.7%respectively.Microhardness may be increased from 320.8HV 0.1 to 363.9HV 0.1.The residual compressive stress may be changed from-420.38 MPa to-621.25 MPa.The surface peaks are removed.A dense layer is formed on the surface,and the grain structure is refined.The diffraction peak is shifted and the greater residual compressive stresses are introduced.