Effect of Zr on the microstructure of 6061 Aluminum alloy during SIMA process

In this study the effect of adding Zr on the microstructure of 6061 Al alloy during SIMA process has been investigated. The optimum amount of Zr containing master alloy for proper grain refining was obtained as 0.3 wt.%. After that SIMA process employed hydraulic press, recrystallization and partial melting (RAP) to obtain a fine globular microstructure. 40% strain, various heat treatment temperatures (605 to 645°C) and holding times (30 and 40 minutes) were investigated to reach an optimized fine globular microstructure. Microstructural study which was carried out bythe optical microscopy and MIP software exhibited the uniform equiaxed recrystallized grain structure. Observations showed that the presence of grain refining agents lead to finer distribution of intermetallics and more globular microstructure during SIMA process