Study On Ultrasonic Strengthening Process Of Wear Resistant Surface Of Aviation Spherical Plain Bearing

Aviation spherical plain bearing is one of the important components of aircraft engine.Since its rotation speed is relatively slow,it cannot form dynamic pressure lubrication like rolling bearing,so its lubrication conditions are poor,and it is very easy to wear.Therefore,this research proposes a ultrasonic rolling strengthening technology to substantially improve the wear resistance of aviation joint bearings.This technology enhances the wear resistance of the joint bearing mainly by improving the surface quality of the joint bearing,reducing its surface roughness,increasing the micro-hardness of the surface,increasing the residual compressive stress on the surface and reducing the shear stress.There are many materials used in the manufacturing of aviation joint bearings,but the more common used materials are titanium alloy and stainless steel.In this research,the titanium alloys have been used to conduct experiments.Initially,by using theoretical formulas,the study derives different types of horns such as catenary horns,exponential horns,conical horns and stepped horns,and then selected the ones that are suitable for this test.The influence of static pressure on the residual stress and shear stress on the surface of the titanium alloy is obtained through simulation.Then,its surface morphology was observed through different process parameters of ultrasonic rolling for titanium alloy,and measure its surface roughness,micro-hardness,surface residual stress and shear stress were measured to reveal the case of ultrasonic rolling’s influence on titanium alloy.Experimental research and simulation results show that the selection of conical and stepped composite horns has the largest amplification factor and the greatest impact on titanium alloys.Appropriate static pressure,rolling time and spindle speed can significantly improve the surface quality of titanium alloy,reduces the surface roughness and shear stress respectively,and increase the micro hardness and residual stress of titanium alloy.Too high and too small process parameters cannot effectively improve the surface wear resistance of the titanium alloy,and even backfire aggravates the wear on the surface of the titanium alloy and sharply reduces the fatigue life of the joint bearing.The simulation results had conformity with the above rules.