Thermal conductivity is a key parameter for high performance material needed for electronic devices. While most commercially used Mg foundry alloys exhibit low thermal conductivities. In this work, we developed an Mg–3RE–0.5Zn alloy that is suitable for high pressure die cast (HPDC) ultrathin wall cellphone components. The thermal conductivity of this alloy was measured to be 133.9 W/(m·K) at room temperature, approximately 85% that of pure Mg (156 W/(m·K)). Meanwhile, it exhibited acceptable room-temperature mechanical properties with high yield strength of ∼153 MPa, ultimate tensile strength of ∼195 MPa, and elongation of ∼4.3%. The excellent combination of superior thermal conductivity and high strength is attributed to low solute atoms in the α-Mg matrix and the formation of networked (Mg, Zn)₁₂RE eutectic phase. The results from this study will be helpful for developing new HPDC Mg alloys with more excellent performances and promoting the wider application of Mg alloys.

热导率是电子设备所需高性能材料的关键参数。虽然大多数商业使用的镁铸造合金表现出低热导率。在这项工作中，我们开发了一种适用于高压压铸 (HPDC) 超薄壁手机组件的 Mg-3RE-0.5Zn 合金。该合金的热导率在室温下测得为 133.9 W/(m·K)，约为纯镁 (156 W/(m·K)) 的 85%。同时，它表现出可接受的室温机械性能，屈服强度为~153 MPa，极限拉伸强度为~195 MPa，伸长率为~4.3%。卓越的导热性和高强度的完美结合归因于 α-Mg 基体中的低溶质原子和网络 (Mg, Zn) _{12 的形成}RE共晶相。本研究结果将有助于开发性能更优异的新型HPDC镁合金，促进镁合金的更广泛应用。