Analysis on the transformation of melt wear to self-healing crack of wire arc additive manufactured Al 5356 alloy

In this present work, the nanowear test of wire arc additive manufactured Al5356 alloy showed the plastic deformation and melt wear at 3500µN load. However, melt wear and pit formation have occurred at 5500µN that increased the coefficient of friction (CoF) to 0.82. Surprisingly, further increase of load to 7500µN, the surface become smooth and CoF decreased to 0.67 due to the transformation of melt wear to a self-healing zone. The MgO and MgAl₂O₄ formation at the wear track region reduced the CoF as well as the percentage of wear depth at 7500µN. Hence, the specimen exhibited high CoF and wear depth up to 5500µN. Further, increase in applied normal load would reduce both CoF and percentage of wear depth.