Reduction of Spatter Generation Using Atmospheric Gas in Laser Powder Bed Fusion of Ti–6Al–4V

Abstract

Laser powder bed fusion (LPBF), a typical additive manufacturing (AM) process, is a promising approach that enables high-accuracy manufacturing of arbitrary structures; therefore, it has been utilized in the aerospace and medical fields. However, several unexplained phenomena significantly affect the quality of fabricated components. In particular, it has been reported that the generation of spatters adversely affects the stability of fabrication process and degrades the performance of the fabricated components. To realize high-quality components, it is essential to suppress the generation of spatters. Thus far, the suppression of spatter generation has been attempted based on the process parameters; however, this has not been adequately discussed in terms of the fabrication atmosphere. Therefore, in this study, we focused on the fabrication atmosphere and investigated spatter generation using gas with different physical properties rather than conventionally used argon. It was observed that the spatter generation during the fabrication of the Ti6Al4V alloy could be significantly suppressed by changing the atmospheric gas, even under constant LPBF process parameters. We proved that the fabrication atmosphere is an important factor to be considered, apart from the process parameters, in AM technology.

Review—Importance of Atmospheric Gas Selection in Metal Additive Manufacturing: Effects on Spatter, Microstructure, and Mechanical Properties

“…In Ti6Al4V alloys, the effect of oxygen (O 2 ) contained in the atmosphere during the fabrication process on the generation of spatter and the effect of changing the atmospheric gas to He gas has been reported using single-layer basic evaluation equipment that imitates L-PBF. 36) Figures 1 and 2 show the graphs of the state of spatter generation and the weight of the recovered spatter when O 2 , which is an impurity component, is added to He in addition to the conventional atmospheric gas Ar. As the O 2 concentration in the Ar and He atmospheres increased, the amount of spatter increased significantly; with a He atmosphere, the generation of spatter was more suppressed compared to an Ar atmosphere.…”