High-speed X-ray investigation of melt dynamics during continuous-wave laser remelting of selective laser melted Co-Cr alloy

The objective of this study is to quantify the melt pool dynamics during continuous wave laser remelting of a Co-Cr alloy manufactured using selective laser melting. This knowledge will inform process improvement and numerical modeling of laser remelting. A high-intensity X-ray beam imaged a 2 mm x 0.5 mm area of the surface with a 50 kHz framerate. Analysis of these videos quantified the melt pool surface wave movement and compared this to the initial surface features. The results indicate that the keyhole and its characteristic oscillations can suppress large wavelength features on the initial surface. (C) 2019 Published by Elsevier Ltd on behalf of CIRP.