Patent attributes
The invention relates to a method producing parts using laser sintering wherein a fusible powder is exposed to a plurality of laser scans at controlled energy levels and for time periods to melt and densify the powder and in the substantial absence of particle bonding outside the fusion boundary. Strength is improved up to 100% compared to previous methods. An example includes a relatively high energy initial scan to melt the powder followed by lower energy scans controlled to densify the melt and separated in time to dissipate heat to the surrounding part cake. The rate and extent to which the powder particles are fused together can be controlled so that each successive scan can be used to fuse the particles together in discreet incremental steps. As a result, the final dimensions of the part and its density and mechanical properties can be improved compared to conventional methods and part growth avoided.
