Powder degradation in laser powder bed fusion process

Ahmad Raza, Eduard Hryha

Chalmers University of Technology, Sweden

Powder reusability is a critical aspect of powder based additive manufacturing techniques to reduce the cost and increase sustainability of the process. In laser powder fusion (LPBF) process, powder degradation is on smaller extent governed by powder oxidation and on large extent by spatter accumulation. In this presentation, spatter oxidation of several alloys including AlSi0Mg, Alloy 718, HX alloy, and Ti64 alloy will be briefly discussed. One thing which is common in all various spatter particles is the extent of oxidation, which is usually significantly higher than powder bed. An interesting aspect of study on spatter is the oxidation behavior of various alloys. For example, Al based alloy showed the formation of columnar structure on spatter particle surface. However, Alloy 718 showed the formation of particulates and patches of oxides. The effect of such oxidized particles will adversely effect the properties of final product. Therefore, it is important to be studied.