MgAl_2O_4和MgO混合物对8079铝合金组织的影响

Effects of MgAl_2O_4 and MgO Mixture on Microstructure of 8079 Aluminum Alloy

采用X射线衍射(XRD)、金相显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)等检测手段,研究了MgAl_2O_4和MgO混合物对8079铝合金晶粒大小及第二相形貌和尺寸的影响。结果表明,MgAl_2O_4和MgO对8079铝合金组织有明显的变质作用。随着MgAl_2O_4和MgO添加量的增加,8079铝合金的晶粒尺寸逐渐减小,针状第二相Al_3Fe尺寸也逐渐变小且形貌由针状向点状转变。当加入0.05%的MgAl_2O_4和MgO的混合物后,8079铝合金的晶粒尺寸可细化至约30μm,针状第二相Al_3Fe的形貌则变为断续的点状。

The effects of the mixture of MgAl2O4 and MgO on the grain size and the morphology of second phase in 8079aluminum alloy were investigated systematically by XRD（X-ray diffraction）,OM（optical microscopy）,SEM（scanning electron microscopy）and EDS（energy dispersive spectrometer）.The results show that MgAl2O4and MgO have obvious refinement effect on the microstructure of 8079aluminum alloy,and they can modify the morphology of needle-like Al3Fe.With the increase of the mixture of MgAl2O4 and MgO,the grain size of the 8079aluminum alloy is decreased gradually,and the needle-like phase becomes smaller with the shape modified to particle.With adding a mixture of 0.05%MgAl2O4 and MgO,the grain size of 8079aluminum alloy can be decreased effectively from more than100μm to about 30μm,and the shape of need-like Al3Fe phase is converted into particle structure.