The Influence of Laser Power and Scan Speed on the Single Layer Bead Dimension of Polylactic Acid Powder

Abstract

Selective Laser Melting (SLM) is particular Additive manufacturing technologies, is gaining popularity to manufacture complex components from polymer materials. This technique uses low power density laser to melt and fuse polymer powder, and can produce near net-shaped parts up to 99.9% relative density. The objective of this investigation was to understand the influence of laser power and scan speed on the bead of single layer PLA powder bed. SLM trials were carried out at laser power 0f 4-20Watt, scan speed of 8.33 mm/s, 16.66 mm/s, 33.32 mm/s and 50 mm/s. The dimension of single layer bead, width, and height, was characterized as a function of laser power and scan speed. From the results of observations, it turns out that laser power is a factor that greatly affects the dimensions of melt results. The greater the laser power the wider the melt results, while the effect of laser power on the height of the single layer bead is not consistent. Width to height ratio describes the form of melt, fat or slim. At low laser power tends to form fat, which is shown by a small width to height ratio, the larger the laser power the slimmer the shape, shown by a large width to height ratio. The optimum bead dimension can be produced at 1.6 to 3.3 cm/s for laser power up to 20 Watt. For a wider range of scan speeds, the optimum bead dimension can be obtained at laser power below 12 Watts