Quantification of recrystallization behavior and dispersoids with Rietveld refinement in 3004 aluminum alloy with various homogenization conditions

The effect of homogenization conditions (heating and cooling rates) on phase transformation and precipitation behavior of 3004 aluminum alloy during annealing was investigated with X-Ray diffraction/Rietveld refinement. Mass fraction of Al matrix, Al6(Mn,Fe) and α-Al12(Mn,Fe)3Si before and after annealing at 723 K was examined by X-ray diffraction (XRD) and Rietveld refinement technique. Powderization of samples was useful to eliminate the effect of prefered orientation (texture) and coarse crystal grains on diffraction intensity. As a result, mass fraction change of phase transformation of primary particles and precipitation during annealing at 723 K was successfully evaluated. More precipitates due to slow heating and cooling rate for the homogenization treatment influence microstructures and mechanical properties in the latter process, such as work hardening, anneal softening and precipitation during annealing. With applying this knowledge, desirable microstructures and mechanical properties can be obtained.