铝硅合金是汽车工业进行材料轻量化设计的常用材料，为满足重型汽车用液力缓速器定转子零件上的轻量化应用需求，选择新型 Al-12Si-3.5Cu-0.4Mg 铸造铝合金为研究象。 研究了实验合金的 T6 热处理(固溶+时效)工艺，以及 T6 热处理对实验合金干摩擦性能的影响。 结果表明，铸态实验合金的组织主要由初生 α-Al 相、共晶 Si 相和 Al2Cu相组成。 固溶热处理后，共晶 Si 相球化，Al2Cu 相溶入基体。 时效热处理后，基体中弥散析出了大量纳米级 θ′相。 铸态实验合金的 T6 热处理工艺为 470 ℃固溶 12 h，水冷，随后 180 ℃时效 10 h，空冷。 T6 热处理后，铸态实验合金的室温力学性能显著提高，抗拉强度和硬度分别从铸态的 221 MPa 和 92 HV 提高到 322 MPa 和 144 HV。 同时，T6 热处理也显著提高了铸态实验合金的干摩擦性能，这主要归因于 T6 态实验合金的高硬度，导致磨损产生的磨粒不易被压入基体，并产生更多的氧化物。

Al-Si-based alloys are commonly used for lightweight material design in the automotive industry. To meet the lightweight application requirements of fixed rotor parts of hydraulic retarders for heavy-duty vehicles, a novel Al-12Si- 3.5Cu-0.4Mg cast aluminium alloy was selected as the research object. The T6 heat treatment process of the experimental alloys and its effect on the dry friction performance were investigated. The microstructure of the as-cast experimental alloy is mainly composed of a primary α-Al phase, eutectic Si phase, and Al2Cuphase. After solution treatment, the eutectic Si phase is spheroidized, and the Al2Cuphase dissolves into the matrix. After aging treatment, a large amount of the nanosized θ′ phase is dispersed and precipitates in the matrix. The T6 heat treatment process for the as-cast experimental alloy was as follows: solution at 470 ℃ for 12 h and water cooling, followed by aging at 180 ℃ for 10 h and air cooling. After T6 heat treatment, the room temperature mechanical properties of the as-cast experimental alloy significantly improved, with the ultimate tensile strength and hardness increasing from 221 MPa and 92 HV in the as-cast state to 322 MPa and 144 HV, respectively. Moreover, the T6 heat treatment significantly improves the dry friction performance of the as-cast experimental alloy. The main reason is the high hardness of the T6 state experimental alloy, which makes it difficult for the abrasive particles generated by wear to press into the matrix and produce more oxides.