5G基站散热器用高导电(热)压铸Al-Si-Fe铝合金的热力学设计与试验

Thermodynamic Design and Experiment on High Conductivity Die-casting Al-Si-FeAluminum Alloy for 5G Base Station Heat Sink

针对5G基站中压铸铝散热壳体强度与电(热)导率之间的倒置问题,通过热力学计算与试验研究相结合,利用PANDAT热力学计算、金相显微镜、扫描电镜、X射线衍射仪以及透射电镜研究了时效处理对压铸Al-7.5Si-0.8Fe铝合金的显微组织以及导电性能的影响。结果表明,320℃×1 h时效处理能够显著提升压铸铝合金的电导率,时效组织中沿晶界和晶内分别析出了Al-Fe-Si三元相和Si相,降低了Fe、Si元素在铝基体中的固溶度。另外,经过时效处理,共晶Si网链连续性变差、铝基体的连通性增强也是电导率提升的主要原因。

In view of the inversion problem between strength and electrical(thermal)conductivity of die-cast alumi⁃num heat sinks in 5G base stations,effects of aging treatment on microstructure and conductivity of die-cast Al-7.5Si-0.8Fe aluminum alloys were investigated through a combination of thermodynamic calculations and experimental research by PANDAT thermodynamic calculations,metallographic microscopy,scanning electron microscopy,X-ray diffraction,and transmission electron microscopy.The results indicate that the conductivity of alloy is significantly improved after heat aging treatment at 320℃for 1 h.Al-Fe-Si ternary phases and Si phase are precipitated along the grain boundaries and interior,respectively,thus reducing the solid solubility of Fe and Si in Al matrix.In addition,the continuity of eutectic Si network is deteriorated after aging,accompanied with the increased connectivity of the alumi⁃num matrix,which is the main reason for the enhancement of conductivity.