Abstract: Effect of homogenization process on microstructure, iron-rich phase transformation, element distribution and dispersion phase uniformity of 6014 aluminum alloy was studied by means of bright and dark field images of optical microscope, differential scanning calorimetry, scanning electron microscope, transmission electron microscope. The results show that the dendrite segregation and non-equilibrium eutectic structure are found in the 6014 aluminum alloy ingot, the element content fluctuates greatly, and the grain is equiaxed. The content of the second phase in the ingot is significantly higher than that after homogenization treatment. Due to the different morphology and distribution of the second phase, it can be divided into α-AlFeMnSi, β-AlFeSi, Mg₂Si and Q-AlCuMgSi phase, respectively. After two-stage homogenization at 560 ℃ for 4 h and 540 ℃ for 6 h, the reticular dendrites are not completely broken. When the holding time of first-stage homogenization at 560 ℃is extended to 12 h, more β-AlFeSi phase is transformed into α-AlFeMnSi phase. After single-stage homogenization at 560 ℃for 19 h, the dendrites are basically changed from reticular morphology to chain morphology. After two-stage homogenization at 580 ℃ for 4 h and 540 ℃ for 6 h, the dispersed α-AlFeMnSi phase is distributed more uniform. When the holding time of first-stage homogenization at 580 ℃ is extended to 12 h, overburing occurrs and the size of the dispersion phase increases which enriches around the grain boundary.

Key words: 6014 aluminum alloy, homogenization process, microstructure, dispersion phase uniformity