Feasibility study on plastic laser sintering without powder bed preheating

摘要

In a plastic laser sintering machine, the most part of power consumption is spent on heating of powder bed. The powder bed heating is essential to prevent parts from warping during the process. However metal laser melting is normally performed without such heating. During the process, warping is suppressed by fixing the parts to a base plate. In the present research, the same scheme was introduced to plastic laser sintering. A plate of 2mm was successfully obtained. Residual stress was completely relieved by annealing treatment of 30min and permanent deformation was negligible. A relative density of 90%, which is standard level of commercially available part, was obtained. Tensile and impact strength were limited to 1/2 and 2/3 of those obtained by normal process, respectively. Energy consumption of laser module in preheating free process is around 45MJ/kg, and complete robustness against power supply interruption was demonstrated.