Underwater surface remelting of selective laser melted titanium parts
Tae Woo Hwang, Sang Wook Han, Taekyung Lee, Ji Hoon Kim, Chester J. VanTyne, Young Hoon Moon
Abstract
The selective laser melting (SLM) process suffers from a relatively low surface quality in the produced parts. Laser surface remelting has been studied as a reasonable solution to this limitation. Previous studies of the remelting process mostly focused on enhancing the surface quality in gaseous atmospheres. In this study, we proposed an underwater laser remelting process to better control the surface quality of SLM parts. In order to systematically characterize this new process, laser surface remelting experiments were carried out underwater and in argon atmospheres on SLM parts made of Ti-6Al-4 V powder. The effects of processing parameters, namely the remelting repetition times, beam scanning pattern, and fill-spacing on the resultant surface roughness and hardness were analyzed. The results show that laser surface remelting in the underwater environment can be a feasible and effective alternative method to control the surface quality of titanium parts processed by SLM.