Densification mechanism and microstructural evolution in selective laser sintering of Al-12Si powders

摘要

The role of processing parameters on the densification mechanism and microstructural evolution in laser sintered Al-12Si powder has been explored. It was established that both the densification mechanism and microstructural evolution in laser sintered Al-12Si powder were controlled by the specific laser energy input. Analysis of the cross-section of laser sintered microstructures of Al-12Si powders indicated that the tops of the grains in the previous layer are partially re-melted and then undergo epitaxial growth in the next layer where the heat affected zones (HAZ) grain boundaries and solidification grain boundaries (SGBs) are continuous along the fusion boundary.