A Novel Al‐Rich/Ti–6Al–4V Layered Composite with Superior Wear and Electrochemical Behavior

Abstract

By adding a certain amount of Al to the surface of Ti–6Al–4V (TC4) alloy, a novel layered composite composed of TC4 alloy matrix and Al‐rich alloy is designed and successfully fabricated by a blended elemental powder metallurgy (BE PM) method. The results demonstrated that after the addition of 1 wt% Al, the layered composite exhibits superior wear and electrochemical behavior over powder metallurgy Ti–6Al–4V (PM TC4) alloy, which indicates that a wear‐resistant and corrosion‐resistant layer can be in situ synthesized on the sample surface. Moreover, the volume fraction of α phase, the thickness of α colonies, porosity, Rockwell hardness, and wear resistance of the layered composites increase significantly with Al addition, resulting in the decrease in area, width, and depth of wear tracks, and the reduction of average friction coefficients (COFs). Furthermore, with the addition of Al, the galvanic effect at the interface of α/β phase reduces, whereas the porosity of the layered composites, the chemical activity, and the corrosion rate of α phase increase significantly. Therefore, the corrosion resistance of the layered composites increases first and then decreases with Al addition, and the optimum value can be achieved when the added amount of Al is 1 wt%.