Effects of magnesium content on phase constituents of Al-Mg-Si-Cu alloys
(1. School of Mechanical Engineering, Shandong Institute of Light Industry, Ji’nan 250100, China;
2. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
2. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
Abstract: By means of scanning electron microscopy(SEM), energy dispersive spectrum(EDS), X-ray diffractometry(XRD) and metallographic analysis, the effects of variation of magnesium content on phase constituents of Al-Mg-Si-Cu alloys were investigated. The results indicate that the constituents formed during casting alloys are main Al1.9CuMg4.1Si3.3，Al4(MnFe)3Si2 and Mg2Si, while pure Si is only present in the alloy containing lower magnesium content. Increasing Mg content leads to increasing the amount of Mg2Si, but decreasing the amount of Al1.9CuMg4.1Si3.3 and Al4(MnFe)3Si2. During the following homogenization process, Al1.9CuMg4.1Si3.3 is completely dissolved, Al4(MnFe)3Si2 and pure Si remain unchanged. After rolling and final heat treatment, the constituents in the alloys change no longer.
Key words: Al-Mg-Si-Cu alloys; phase constituent; magnesium content; Al1.9CuMg4.1Si3.3; Al4(MnFe)3Si2; Mg2Si