Ceramic materials in selective laser sintering process

In the present paper some behavior of ceramic materials for laser sintering/melting processes (SLM/SLS) were evaluated. Experiments were carried out with a 40W CO2 laser, on samples characterized by different particle size distributions within16 and 184 μm, and different laser scan speeds (1-30 mm s-1). In particular, part of the energy supplied by the laser beam is dispersed by different mechanisms of energy transfer. These quantities were estimated to evaluate the process effectiveness in particle melting or sintering, by applying an energy balance that was solved with the use of both experimental data and exchange coefficients, calculated from known empirical correlations. The experimental results show a marked effect of balling in certain regimes of laser irradiation and a considerable dependence of this effect, with the average size of the particle. The increase of the molten mass between 16 μm and 48 μm is 24% at a scan speed of 1 mm s-1 and it is 47% at a scan speed of 5 mm s-1.