Abstract Scope |
Spatter refers to the ejection of powder and molten material that can result in defects such as denudation, contamination, and porosity. The key to effectively reduce spatter is to understand the dynamics of spatter formation, of which connection between processing parameters and spatter formation is missing in the literature. Computer vision was applied on high-frequency X-ray images captured during laser melting to analyze spatter. For different laser power, velocity combinations and powder sizes, the ejection quantity, velocity, and travel distance are different. For instance, delayed ejections were observed for larger powders that can be attributed to induced chamber gas flow instead of recoil pressure. Also, spatter behavior including ejection-to-fall lifetime was quantified as a function of power and velocity for Inconel 718 and Ti-6Al-4V.
This work provides insights regarding dominating mechanisms that contribute to spatter under different processing conditions. This, in turn, can provide guidance for minimizing spatter. |