Abstract: The goal of this paper was to study the effect of initial water atomized powder size and sintering processing conditions on the grain growth and densification behavior of metallic components of 316L stainless steel. Of particular interest was to establish the relationship between grain growth and densification. The results showed that prior to grain growth the pores are attached to the austenite grain boundaries and/or to annealing twins, suggesting two mechanisms; 1) the pores at the grain boundaries act as pinning force to prevent grain coarsening, and 2) the mobility of high angle grain boundaries act as compressing force to reduce the pore size. After grain growth, the pores are left behind the grain boundaries. At this condition, the sintering of the metallic component becomes nearly impossible to achieve. The grain growth and sintering behavior were systematically analyzed using advanced electron optic techniques. The results will be presented and discussed.
Authors: Hsiang-Ling Juan, Y. Zhou, C. Schade, and C.I. Garcia
Keywords: Additive Manufacturing, Binder, Densification, Fractal Dimension, Grain Growth, Sintering