Fabricating a three-dimensional article from powder

摘要

A computer-controlled apparatus and method for fabricating three-dimensional articles in layerwise fashion is disclosed. Upon dispensing a layer of a fusible powder, a laser 110 irradiates selected locations of that layer on a target surface 104 to fuse the powder into a cross-section of the article to be formed in that layer, such that the cross-sections fuse together into the article. The laser 110 is controlled in a raster scan fashion across the selected locations of the powder layer. The raster scan lines are defined, for each cross-section, to achieve an optimal fill scan time. The optimal fill scan time is determined, by the computer 140 estimating the fill scan time by rotating the cross-section over a plurality of rotational angles, and estimating the fill scan time for each of the rotated cross-sections for at least a sample of the fill scans necessary to form the article. The actual fill scan vectors to be used in selective laser sintering of the article are rotated, from a coordinate axis at the target plane, according to the rotation of the cross-section providing the lowest estimated fill scan time.