The Effect of Shielding Gas on Forming Characteristics for Direct Laser Melting
Direct Laser Melting 공정시 차폐가스가 성형 특성에 미치는 영향

S.W. Han, S.G.R. Shin, B.D. Joo, C.H. Lee, Y.H. Moon
2013 Transactions of Materials Processing  
Direct Laser Melting is a prototyping process whereby a 3-D part is built layer wise by melting the metal powder with laser scanning. This process is strongly influenced by the shielding gas and the laser operating parameters such as laser power, scan rate, layering thickness, and rescanning. The shielding gas is especially important in affecting the microstructure and mechanical properties. In the current study, fabrication experiments were conducted in order to analyze the effect of shielding
more » ... effect of shielding gas on the forming characteristics of direct laser melting. Cylindrical parts were produced from a Fe-Ni-Cr powder with a 200W fiber laser. Surface quality, porosity and hardness as a function of the layering thickness and shield gas were evaluated. By decreasing the layering thickness, the surface quality improved and porosity decreased. The selection of which shield gas, Ar or N 2 , to obtain better surface quality, lower porosity, and higher hardness was examined. The formability and mechanical properties with a N 2 atmosphere are better than those parts formed under an Ar atmosphere.
doi:10.5228/kstp.2013.22.6.334 fatcat:q5irmneyvffz7drfah6dtv7qru