Preparation and Wear Behavior of TiN/ Sn Composite Coating on Surface of TLM Titanium Alloy

Abstract

In order to improve the wear resistance of Ti-25Nb-3Zr-2Sn-3Mo(TLM) titanium alloy, the composite coating on surface of alloy was prepared by surface mechanical composite strengthening(SMCS) process. The microstructure, micromechanical properties and tribological properties of the composite coating were studied. Results showed that TiN/Sn composite coatings could be successfully prepared on the alloy surface using surface mechanical composite strengthening technology. As the Sn content increased, the thickness and roughness of the composite coating continued to increase, and the thickness of 10%～40% Sn coatings was 9.08, 14.05, 18.33 and 23.55 μm, respectively. Additionally, the surface hardness of 10%～40% Sn coatings was 590, 529, 465 and 400 HV, respectively, which was higher than that of the matrix hardness(～230 HV). Furthermore, the wear amounts of the composite coating decreased first and then increased with the increase of Sn content, and the 20% Sn coating had the lowest wear amount. In the dry wear test, the wear mechanism of original sample was mainly adhesive wear and accompanied by abrasive wear, while the wear mechanism of the composite reinforced sample was abrasive wear, adhesive wear and accompanied by oxidation wear.

Keywords

• tlm titanium alloy；surface mechanical composite strengthening；ti / sn coating；abrasion resistance