(華南理工大學(xué) 國(guó)家金屬材料近凈成形工程技術(shù)研究中心，廣州 510640)
摘 要: 完成不同Mg含量AlSiMgMn合金高真空壓鑄實(shí)驗(yàn)，采用掃描電鏡(SEM)、透射電鏡(TEM)對(duì)合金微觀組織進(jìn)行分析，得出不同Mg含量下時(shí)效析出β″相的密度，并討論其對(duì)力學(xué)性能的影響。通過(guò)差示掃描量熱法(DSC)對(duì)不同Mg含量的合金時(shí)效析出動(dòng)力學(xué)進(jìn)行分析，結(jié)合Arami-Johnson-Mehl方程計(jì)算析出相的析出動(dòng)力學(xué)參數(shù)。結(jié)果表明：Mg含量較少時(shí)，時(shí)效強(qiáng)化效果不明顯，隨著Mg含量的提高，時(shí)效強(qiáng)化效果逐漸提高；Mg含量的增加顯著提高合金中β″相的數(shù)密度，β″相為合金時(shí)效強(qiáng)化的主要影響因素；隨著Mg含量的增加，達(dá)到峰值時(shí)效的時(shí)間越長(zhǎng)，且β″相析出激活能增大。
關(guān)鍵字: AlSi10MgMn合金；高真空壓鑄；時(shí)效強(qiáng)化；析出動(dòng)力學(xué)
（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
