Modeling of near infrared pulsed laser sintering of metallic powders

Using pulsed near infrared laser radiation for selective laser sintering bears several advantages compared to cw sintering such as low required average power, less residual heat and improved lateral precision. By adapting the pulse length (and thus the heat diffusion length during the pulse) to the grain size of the used metal powder, the laser pulse energy can mainly be deposited in the skin of the powder particles where heating and melting is obtained, whereas the centers of the grains remain at much lower temperature and act as heat sinks after consolidation. The model described here was numerically implemented and experimentally tested with a pulsed Nd:YAG laser on titanium powder. The results of the model predictions and the performed experiments are in good agreement.