Effect of T6 treatment on additively-manufactured AlSi10Mg sliding against ceramic and steel

In this study, the tribological properties of an AlSi10Mg alloy that was fabricated using laser powder bed fusion, an additive manufacturing technique, was investigated in both the as-built (but stress-relieved) and T6-treated condition. The stress-relieved condition consists of elongated Al grains and a dendritically-arranged nano-crystalline Si-phase. T6 treatment, a conventional heat treatment for cast AlSi10Mg alloys, caused this Si phase to dissolve, re-precipitate and coarsen, which resulted in a loss of hardness, toughness and strength. Dry sliding wear tests were conducted against both a bearing stainless steel and a much harder SiC, and with the sliding direction either perpendicular or parallel to the building direction. In almost all conditions it was found that the T6 treatment either had no statistically significant effect on the wear rate or was detrimental. •In the stress-relieved condition, the wear performance is isotropic.•Wear anisotropy occurred in the T6 condition.•The wear rate against steel is more severe than against SiC.•Frictional response is not necessarily indicative of wear performance.•T6 treatment is generally not recommended for sliding wear performance.