Influence of heat treatment on microstructure, texture and mechanical properties of a selective laser melted AlSi10Mg alloy

The influence of heat treatment on microstructure, texture and mechanical properties of a selective laser melted (SLMed) AlSi10Mg alloy was investigated systematically via microstructure characterization and mechanical characteristics evaluation in the present study. The results show that heat treatment has a great influence on the microstructure, texture and mechanical properties. Both annealing treatment and solution treatment can reduce the hardness significantly, whereas the peak aging treatment almost can’t improve the hardness. No heat treatment corresponds to the highest strength and moderate elongation, annealing treatment corresponds to the lowest strength and highest elongation, and peak aging treatment corresponds to the worst performance. The as-built specimen is comprised of a fine equiaxed grain structure and a typical cellular structure surrounded by continuously distributed particles. After heat treatment, the original equiaxed grain structure and Si particles became coarse, and the cellular structure completely vanished. In comparison with annealing treatment, peak aging treatment results in a coarser grain structure and additional β ′′ precipitates. Before heat treatment, the as-built specimen possesses a very weak texture composing of rotated Cube orientation. After heat treatment, the texture is enhanced and the Cube {100} orientation is dominant. Finally, the relationship between heat treatment and yield strength is quantitatively discussed.