Control of laser sintering in metallic powders

Optimization of laser sintering of submicron metal powders is studied in connection with unsteady heat transfer in a porous layer under simultaneous phase transformations. The eating/cooling rates and the depth of the sintered layer are estimated after analysis of geometrical characteristics of the metallic powder. Computer modeling revealed that the control parameters of the process are the scanning velocity and the permeability coefficient which depends on porosity and structure of the powder layer. At high porosity $>70\%$, the mechanism of heat transfer drastically changes and an approximation of continuum becomes incorrest which degrades the quality of the sintered layer.