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 (λ₂), 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 λ₂. The T6-heat treatment has affected the length of the as-cast dendritic scale, increasing the λ₂ 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.

中文翻译：

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水平凝固和T6 /热处理汽车AlSiMg合金样品的干磨损行为和抗​​性研究

为了研究铝基汽车合金中的干磨损行为，已经对Al7Si0.3Mg合金（重量％）进行了使用水冷定向凝固装置的瞬时水平凝固实验。在距冷却界面2、4、6、40和80 mm的位置（P）处对铸锭样品进行沉淀硬化热处理（T6型）。在以下条件下进行了热处理：在520±2°C下固溶处理3 h​​，然后在温水（70±2°C）中淬火，在155±2°C老化3 h并在空气中老化-冷却。对铸态和热处理样品均进行了干磨测试。磨损测试是通过旋转固定式球磨机进行的。分析的参数是凝固生长和冷却速率（V _L和Ť _{- [R} ），仲树突间距（λ ₂），和磨损体积和速率（w ^ _V和w ^ _{- [R} ）。这些参数之间的相互关系已经进行和实验数学公式已经被提出来表征w ^ _V和w ^ _{- [R}的依赖P，V_大号，Ť _{- [R}和λ ₂。在T6热处理影响了铸态树突标尺的长度，增大λ ₂值以及所研究的汽车合金的磨损特性。铸态和热处理样品分别具有更好和更粗糙的树枝状微观结构。已经对铸态和热处理样品中的枝晶间区域的占据面积分数（％IRAF）进行了耐磨性评估。在铸态和热处理样品中分别观察到较高和较低的IRAF值。