Influences of Scanning Strategy Effect on Surface Roughness in Selective Laser Melting

• Main Authors: Wei, Zhi-Xuan, 魏志軒
• Other Authors: Chang, Shyang-Jye
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/92sv25

碩士 === 國立雲林科技大學 === 機械工程系 === 105 === Selective laser melting (SLM) is a powder-based additive manufacturing technology that capable to fabricate complex geometry parts near full density. Due to layer-by-layer process with high intensity of laser power, the defects such as, deformation, residual stress, thermal accumulation are able to worst the surface roughness. Several studies have investigated the process parameters that affect surface quality. However, several researchers ignore the importance of scanning strategy. Therefore, the aim of this research attempt to analyze to scanning strategy effect to the surface roughness. In the beginning of experimental design, the volumetric energy density (VED) is used to generate continuous single tracks. Secondary, the Taguchi method is conducted to investigate the relation between warpage and fundamental parameters (laser power, scanning speed, overlap and scanning angle) to fabricate stable and undistorted specimens. Finally, several scanning strategies (offset scanning, line scanning, meander scanning, meander scanning with hatch vector, and lightning scanning) are applied to explore the influences to surface quality. Results show meander scanning and lightning scanning are capable to generate consistent specimens without large deformation. The process parameters, such as increased of 45° angle scanning direction and 30% overlap, can optimized the surface quality under this two scanning strategies. Lower scanning speed (500mm/s) is more appropriate to generate to lower Ra of specimens, except the condition under the lightning scanning with increased 45° angle scanning direction. To sum up, this study may lead to contribute to the growing understanding of scanning strategy in selective laser melting.