Sn冷铜型方法对铸造Al-Si-Mg合金组织和力学性能的影响

Effect on the Microstructure and Mechanical Properties of Al-Si-Mg Alloy with Sn-cooling Copper Mold

选用金属Sn为冷却介质,将Al-Si-Mg铝合金熔体浇注到预制的模型中,制备Ф10mm的棒状试样,并且对合金的组织和力学性能进行了研究。结果表明,应用Sn冷铜型方法,可以将试样的晶粒尺寸细化到5μm,与相同条件下水冷铜型得到的试样(8μm)相比,晶粒尺寸细化了37.5%;铸态组织的显微硬度提高了33.3%(Sn冷铜型:80HV0.05;水冷铜型:60HV0.05),试样的抗拉强度提高了22.9%(Sn冷铜型:220MPa;水冷铜型:179MPa)。Sn冷铜型方法可以明显细化合金组织,提高合金的力学性能,有很好的应用前景。

The melt of casting Al-Si-Mg aluminum alloys was cast into the mold cooled by Sn, then bar shape samples with a diameter of 10 mm were prepared. Microstructure and mechanical properties of the alloy were studied. The results shows that, compared with water cooling copper mold, microstructure with grain size of 5 μm in diameter could be obtained by Sn-cooling copper mold technique, which was refined 37.5% than that made by water-cooling copper mold （8 μm ）; micro-hardness （HV） was improved 33.3% （Sn-cooling copper mold： 80 HV0.05; water-cooling copper mould： 60 HV0.05） and ultimate tensile strength （UTS） was improved 22.9% （Sn-cooling copper mold： 220 MPa; water-cooling copper mould： 179 MPa ）. Therefore, Sn-cooling copper mold technique could obviously refine microstructure, improve mechanical properties and have a potential prospect in practical applications.