Hybrid high-temperature wear mechanisms of additive manufactured Ti-6Al-4V alloy

Abstract

This study investigates the high-temperature wear of additive-manufactured Ti6Al4V alloy against GH2132. The wear mechanism transitioned from abrasive and adhesive wear to oxidative wear with rising temperatures. The microstructure characteristics reveal the special hybrid high-temperature wear mechanisms: shear deformation-induced wear hardening and dynamic recrystallization-induced wear softening. At lower temperatures, the thinner oxide layer was easily removed and the worn surface in contact underwent work hardening, reducing the negative effects of thermal softening. At higher temperatures, the thicker oxide layer slightly reduced adhesive of the substrate but failed due to cracking and spalling. Combined with intensified thermal softening, recrystallization softening on the worn surface not only eliminated surface hardening but led to a sharp decline in wear resistance.