Enhanced wear resistance of TiBw/Ti-6Al-4V induced by ultrasonic peening

A discontinuously reinforced titanium matrix composite was fabricated using laser solid forming and subsequently subjected to ultrasonic peening (USP). USP treatment resulted in pronounced grain refinement of the Ti-6Al-4V matrix, accompanied by substantial increases in compressive residual stress (CRS) and microhardness. With increasing USP duration, αTi grains were refined to the nanoscale, primarily driven by dislocation motion. The maximum CRS and microhardness of specimens peened for 8, 16, and 32 min were −921.9 MPa and 594.5 HV 0.025 , −1063.8 MPa and 631.8 HV 0.025 , −1175.4 MPa and 689.3 HV 0.025 , respectively. Moreover, compared to the untreated sample, the wear volumes of specimens peened for 8, 16, and 32 min decreased by 11.6%, 25.6%, and 32.9%, respectively. Abrasive wear remained the dominant wear mechanism.