原位反应制备新型Al-Mg中间合金及其对8079铝合金组织的细化作用

Study on Microstructure Refinement of 8079 Aluminum Alloy by In-situ Reaction Preparation of New Al-Mg Master Alloy

探索了一种采用熔体法原位制备含MgAl2O4尖晶石相的Al-Mg中间合金新工艺。采用金相显微镜(OM)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X-射线能谱仪(EDS)等检测手段,研究了Al-Mg中间合金及其对8079铝合金晶粒大小及组织形貌和尺寸的影响。结果表明,Al-Mg中间合金对8079铝合金组织有明显的细化作用。显著改善了8079铝合金组织形貌,大尺寸的树枝晶碎裂成为短杆状等轴晶;当Al-Mg中间合金的添加量为3%,α-Al的最小尺寸可达30μm。

In this paper,a new process of Al-Mg master alloy containing in-situ MgAl2O4 particles was explored by melt method.The Al-Mg master alloy was characterized by optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),and X-ray energy dispersive spectroscopy(EDS).The effects of Al-Mg master alloy on the grain size were observed.The results show that the Al-Mg master alloy has obvious refinement effect.The Al-Mg master alloy can significantly refine the microstructure of 8079 aluminum alloy.Large-sized dendrites are broken into short rod-like equiaxed crystals.When the Al-Mg master alloy is added,the grains can be remarkably refined,and the minimum size ofα-Al can be 30μm.