Research on Dry Sliding Wear Performances of Hot-dip Aluminized TC4 Alloy

The aluminized TC4 alloy was prepared by hot-dip aluminizing and subsequently high-temperature annealing treatment. The morphology,phase and compositions of aluminized coating were characterized with SEM,XRD and EDS.Dry sliding wear behaviors at different velocities and loadings were conducted for the aluminized and uncoated TC4 alloy on a pin-on-disc wear tester,and the wear mechanism was also explored.The results show that the coating is mainly composed of TiAl₃ combined well to the substrate with a smooth surface. Compared with uncoated TC4 alloy,the aluminized coating has a more excellent wear resistance at sliding velocities of 0.5 ~4 m/s under the same loads.The aluminized and uncoated TC4 alloy present a similar variation of wear rate as a function of velocity.At 0.5 ~0.75 m/s,the wear rate first decrease and then increase rapidly,reaching the top value at 2.68 m/s.Furthermore,the wear rate decreases again from 2.68 to 4 m/s.The main wear mechanism at 0.75 m/s is adhesive wear and abrasive wear,while it is delamination wear at 2.68 m/s and slightly oxidative wear at 4 m/s.