Design of a laser control system with continuously variable power and its application in additive manufacturing

Abstract

Selective laser sintering (SLS) is one of the most popular industrial polymer additive manufacturing processes with applications in aerospace, biomedical, tooling, prototyping, and beyond. SLS is capable of creating unique, functional parts with little waste and no tooling by using a high-powered laser to selectively melt powdered polymer into desired shapes. This process relies heavily on understanding and controlling the thermodynamics of the polymer melt process. One of the biggest challenges SLS faces is lack of adequate process control, which leads to comparatively high component variations. It has been shown that implementing more advanced laser control techniques enable a higher level of control over the processing temperatures and lead to more uniform components. Currently, there are no commercial options for a laser power controller that allows continuously variable power to be used as a galvanometer system adjusts the laser position. This paper will also discuss the development and implementation of a galvanometer controller solution that works in conjunction with an off-the-shelf unit to enable this crucial functionality and will present results showing that, when applied to the SLS process, a 33 % reduction in thermal variation was achieved.