Numerical Simulation and Experimental Comparison on Single Track of Selective Laser Melting Process

• Main Authors: Liou, Yao-Wen, 劉耀文
• Other Authors: Cheng, Chung-Wei
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/80147820061682144820

碩士 === 國立交通大學 === 機械工程系所 === 104 === In this thesis, effects of the processing parameters such as laser power and scanning speed on single molten tracks formed are investigated during the selective laser melting (SLM) Process. The simulation results solved from commercial finite element software (ANSYS 14.0) are validated by the experimental results. Thirty single molten tracks were formed by the laser wavelength 1070 nm, laser focused beam diameter 40 μm, and laser power of 60 W and 79 W with scanning speeds in the range of 10 ~ 150 mm/s. The best formed continuous tracks are determined by measuring the surface morphology of single tracks from the optical microscopy. The experimental results show that the best continuous tracks are formed at a scanning speed from 50 to 90 mm/s at the laser power of 60 W and from 40 to 100 mm/s at the laser power of 79 W. At the laser power of 79 W, we obtain two line charts with variation of scanning speed from measuring the interface width from the cross section morphology of single tracks by the Scanning Electron Microscope and analyzing the remelted depth from the cross section morphology of single tracks by the Energy Dispersive X-ray Analyzer. Both of the two line charts decrease slowly with the increasing of scanning speed. When the scanning speed reaches a critical state (130 mm/s), the line chart of the remelted depth drops drastically. In the numerical simulation, this study taking account of the absorption penetration depth in the powder bed is different from that obtained in an opaque solid material. This model is applied to the heat source by taking different methods. From analyzing between the simulation and experimental results for the laser power of 79 W and scanning speed regime 40 - 90 mm/s, the percentage error of the interface width is 10 ~ 15 %. The percentage error of the remelted depth between simulation and experimental results for the laser power of 79 W and the scanning speed of 40 or 60 ~ 100 mm/s is 15 ~ 30 %.