Movement of powder bed material during the selective laser sintering of bisphenol‐A polycarbonate

Purpose The purpose of this paper is to report on a study of the movement of the powder bed material during selective laser sintering (SLS) of bisphenol‐A polycarbonate (PC) powder and its effect on the morphology of the sintered specimen. Design/methodology/approach Two sintering experiments, i.e. single‐spot laser sintering and raster‐scan laser sintering, were carried out and the material movement mechanisms were investigated in situ and subsequently by scanning electron microscopy. Findings During the raster‐scan laser sintering process, the movement of the powder was found to be primarily perpendicular to the scanning direction. When sintering at a high laser power, it significantly affected the surface morphology of the sintered specimens and parallel surface bands occurred along the scanning direction. Research limitations/implications Experiments were carried out on a modified laser engraving machine rather than a commercial SLS machine. Practical implications A schematic model of the material movement mechanism for each of the sintering strategies is presented. Originality/value The results further the understanding of the sintering behaviour of the powder bed.