Effect of Al–15Zr master alloy on the microstructure of a 2007 aluminum alloy produced by strain-induced melt activation (SIMA) process

In current research, the influence of Al–15Zr grain refiner on the microstructural of Al-4.0Cu-1.2Pb-1.1Mg-0.8Mn Al alloy has been investigated. The optimum content of Zr to obtain fine-grained structure was found to be 0.3 wt.%. Then SIMA process was applied to the unrefined and Zr-refined alloys. A pre-strain of 30% was applied to all samples and then pre-strained samples were subjected to a various holding times (5–20 min) and temperature (600–625 °C) regimes. Microstructural study was carried out on the alloy by using an optical and scanning electron microscopy (SEM) in both unrefined and 0.3 wt.% Zr-refined samples. The results showed that to achieve desired microstructure during SIMA process, the optimum temperature and time were found to be 615°C and 10 min, respectively. The results show that by applying SIMA process at optimum conditions, the average grain size decreases to 54.7 μm and 52.9 μm in unrefined and 0.3 wt.% Zr-refined samples, respectively. The sphericity of grains also increases to 0.754 in unrefined and 0.82 in 0.3 wt.% Zr-refined specimens

کلیدواژه ها:

Al-15Zr ، 2007Al alloy ، SIMA process