Study On The Fretting Damage Behavior And Mechanism Of TC4 Titanium Alloy

TC4 titanium was widely applied in aerospace and other fields because of its high specific strength and good resistance of high temperature and corrosion.However,its performance of fretting damage was poor and restricted its application and development.The fretting damage often leaded to the failure of the engine blade.Shot peening and surface coating were the more common methods of intensive treatment at present,but their effect and mechanism were not clear.This paper did a lot of contrast test with different parameters based on the self-design fretting test device,and summarized the laws of fretting damage behavior of TC4 titanium alloy.The results were apply to the research of tenon structure and had a good effect.The results were as follows:The samples with shot peening showed the weak tendency of adhesion compared with the original polished samples.The effect of shot peening to fretting behavior of TC4 was fluctuated with the change of the shot peening intensity.The 0.20 mm A shot peening intensity had a better Comprehensive performance in this work,and fatigue life of the TC4 tenon structure samples with 0.20 mmA treated had the obvious increase.For the line and plane contact condition,when the fretting behavior tended to slip,the samples with 0.20 mmA shot peening intensity treated showed better resistance of fretting wear compared with the original polished samples;when the fretting behavior tended to adhesion,the samples with 0.20 mmA shot peening intensity treated did not perform the obvious improvement.For point contact condition,the positive influence of 0.20 mmA shot peening intensity treated was not obvious.The CuNiIn coating can effectively delayed the contact of the friction pair substrate and protected the substrate well.Experimental results showed that in the initial stage the bulge of the original rough surface was flattened and filled into the nearby pit.With increase of fretting cycles,the contacting surface became flat gradually,and finally entered a steady state accompanied with the local removal of material.