(华南理工大学 国家金属材料近净成形工程技术研究中心，广州 510640)
摘 要: 完成不同Mg含量AlSiMgMn合金高真空压铸实验，采用扫描电镜(SEM)、透射电镜(TEM)对合金微观组织进行分析，得出不同Mg含量下时效析出β″相的密度，并讨论其对力学性能的影响。通过差示扫描量热法(DSC)对不同Mg含量的合金时效析出动力学进行分析，结合Arami-Johnson-Mehl方程计算析出相的析出动力学参数。结果表明：Mg含量较少时，时效强化效果不明显，随着Mg含量的提高，时效强化效果逐渐提高；Mg含量的增加显著提高合金中β″相的数密度，β″相为合金时效强化的主要影响因素；随着Mg含量的增加，达到峰值时效的时间越长，且β″相析出激活能增大。
关键字: AlSi10MgMn合金；高真空压铸；时效强化；析出动力学
（National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, China）
Abstract:High vacuum die casting experiment of AlSiMgMn alloys with different Mg contents was carried out. The microstructure of alloys was analyzed by scanning electron microscopy and transmission electron microscopy. The density of β′′ precipitates of the alloys was obtained, and their effects on mechanical properties were discussed. The differential scanning calorimetry (DSC) was used to determine the effect of Mg content on precipitation kinetics of alloys, and the precipitation kinetic parameters of precipitates were calculated by the Arami-Johnson-Mehl equation. The results show that the effect of age strengthening is not obvious when the content of Mg is low, and with the increase of Mg content, the effect of age hardening is gradually improved; the increase of Mg content significantly increases the number density of β″ precipitate in the alloys, and β″ precipitates are the main influencing factors of aging hardening; as the content of Mg increases, the time needed for reaching peak aging becomes longer, and the β″ precipitate activation energy increases.
Key words: AlSi10MgMn alloy; high vacuum die casting; age hardening; precipitation kinetics
