Development of simulation system for selective laser melting at mesoscopic scale and defects analysis

• Main Authors: YANG, JU-HAN, 楊儒翰
• Other Authors: WU, HSUAN-CHUNG
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/422uj9

碩士 === 明志科技大學 === 材料工程系碩士班 === 106 === Selective laser melting (SLM) is one of additive manufacturing (AM) designed to use high intensity laser as an energy source to melt and fuse selective regions of metallic powder, layer by layer, according to computer aided design data. Compared with traditional processes such as casting and forging, SLM process features high strength, high hardness, abrasion resistance and anisotropy. However, it is also prone to defects such as balling effect, pores etc., resulting in a relatively low density and a large surface roughness. In order to master the key technology of SLM process, we should deeply comprehend the mechanism of complex physical behavior and defect formation in SLM process, and further get the strategies for the effective control of defect formation. This study had developed a mesoscale simulation system, which can treat heat transfer, phase transformation, microfluidic flow and evaporation. The mesoscale simulation also possesses the capability for the analysis of melt pool temperature, melt pool size, surface morphology, balling effect and pores defects. And the simulation system showed the good agreement with experimental results for single laser scan path.