超声滚压工艺对TC4钛合金表面残余应力的影响

Effect of ultrasonic rolling process on the surface residual stress of TC4 titanium alloy

钛合金关节轴承是航空发动机的重要部件之一,但由于其润滑条件较差,极易产生磨损从而导致失效事故。采用超声滚压工艺对钛合金试件表面进行强化试验,以有效增强试件表面耐磨性能和抗疲劳特性,并着重研究静压力、滚压次数和主轴转速等超声滚压强化工艺参数对钛合金表面残余压应力与剪切应力的影响规律。试验结果与理论分析结果表明,残余压应力随着静压力、滚压次数和主轴转速的提高而增大,剪切应力随着静压力、滚压次数和主轴转速的提高而总体减小;滚压后试件表面可获得-2000~-500 MPa的残余压应力和-600~-300 MPa的剪切应力。超声滚压技术可以有效提高钛合金材料表面的残余压应力,并有效降低表面的剪切应力。

Titanium alloy joint bearing is one of the important parts of aircraft engines,but due to its poor lubrication conditions,it is easy to wear and causes failure.The ultrasonic rolling process was used to strengthen the surface of titanium alloy to effectively enhance the wear resistance and fatigue characteristics of titanium alloy workpiece,the effect of ultrasonic rolling strengthening process parameters such as static pressure,rolling times and spindle speed on the residual compressive stress and shear stress on the surface of titanium alloy was analyzed emphatically.The test results and theoretical analysis results show that the residual compressive stress increases with the increase of static pressure,rolling times and spindle speed,and the shear stress decreases with the static pressure,rolling times and spindle speed increase.After pressing,the surface of the workpiece can obtain the residual compressive stress of-2000~-500 MPa and the shear stress of-600~-300 MPa.Ultrasonic rolling technology can effectively increase the residual compressive stress of titanium alloy materials surface,and effectively reduce the shear stress on the surface.