LAUSR

To investigate dry wear behavior in an aluminum-based automotive alloy, transient horizontal solidification experiments using a water-cooled directional solidification device have been performed with the Al7Si0.3Mg alloy (wt%). Samples of the as-cast ingot at positions (P) 2, 4, 6, 40, and 80 mm from the cooled interface were subjected to precipitation hardening heat treatment (T6-type). The heat treatment has been applied under the following conditions: solution treatment for 3 h at 520 ± 2 °C, followed by quenching in warm water (70 ± 2 °C), aging for 3 h at 155 ± 2 °C and air-cooling. Dry wear tests were performed on both the as-cast and heat-treated samples. The wear tests were carried out by rotary-fixed ball wear machine means. The analyzed parameters were solidification growth and cooling rates ( V L and T R ), secondary dendritic spacings ( λ 2 ), and wear volume and rate ( W V and W R ). An interrelation between these parameters has been conducted and experimental mathematical equations have been proposed to characterize the W V and W R dependence on P , V L , T R and λ 2 . The T6-heat treatment has affected the length of the as-cast dendritic scale, increasing the λ 2 values as well as the wear features of the investigated automotive alloy. Finer and coarser dendritic microstructures inherited better wear resistance for the as-cast and heat-treated samples, respectively. An evaluation by occupied area fraction (%IRAF) of interdendritic regions on wear resistance in the as-cast and heat-treated samples has been performed. It has been observed higher and lower IRAF values in the as-cast and heat-treated samples, respectively.