Al-22Si-3Fe-1.8Mn合金中的四元富铁相研究

Quaternary Fe-rich Phase in Al-22Si-3Fe-1.8Mn Alloy

利用X射线衍射仪、扫描电镜(带EDS)和金相显微镜对Al-22Si-3Fe-1.8Mn合金进行研究。结果表明:在铸态试样中存在晶体结构分别与Al8Fe2Si、Al9Fe2Si2和Al3FeSi2晶体结构相同的三种四元富铁相,并确定了其中两种相的化学式分别为Al12Si2Fe2Mn、Al42.5Si11Fe4.7Mn。通过萃取态试样确定了另一种富铁相的化学式为Al15.97Si14.82Fe4.24Mn,并且该相为Al-22Si-3Fe-1.8Mn合金中最先析出的高温相。

For the purpose of understanding the quaternary Fe-rich phases ofhypereutectic Al-Si alloy, Al-22Si-3Fe-1.8Mn alloy was studied by X-ray diffraction, scanning electron microscopy （with EDS） and optical microscopy. The results show that there are three quaternary Fe-rich phases and the crystal structure of them is consistent withAl8Fe2Si、Al9Fe2Si2, A13FeSi2 respectively, and the chemical formula of the two of quaternary Fe-rich phases is determined as Al12Si2Fe2Mn and Al42.5Si11Fe4.7Mn in the as-cast samples. The another chemical formula Al15.97Sil4.82Fe4.24Mn is identified by extracted samples, it＇s the high temperature phase which is first precipitation flom Al-22Si-3Fe-1.8Mn alloy.