US 6,694,207 B2 · Selective laser sintering with interleaved fill scan

Abstract

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 irradiates selected locations of that layer to fuse the powder into a cross-section of the article to be formed in that layer, such that the fused cross-sections fuse together into the article. The laser is controlled in a raster scan fashion across the selected locations of the powder layer. The parallel raster scan lines are separated from one another, centerline-to-centerline, according to a selected pitch, or fill scan spacing value. The positions of the parallel scan lines are determined with respect to a coordinate system at the powder layer, rather than with respect to boundaries of the cross-section being formed; in alternating layers, the parallel scan lines are offset from one another by one-half the pitch. This arrangement of the scan lines optimizes the structural strength of the article being formed, while minimizing the number of scans required to form the article.

Claims17

Dependent claims

A method of fabricating a three-dimensional article, comprising the steps of:

dispensing a first layer of a powder at a target surface;
scanning an energy beam at selected locations of the first layer of powder corresponding to a cross-section of the article, in a first plurality of parallel scan lines, adjacent ones of the first plurality of parallel scan lines having a selected pitch and at positions of the first layer of powder defined relative to a coordinate axis of the target surface;
then dispensing a second layer of powder over the first layer;
scanning the energy beam at selected locations of the second layer of powder corresponding to another cross-section of the article, in a second plurality of parallel scan lines, adjacent ones of the second plurality of parallel scan lines at the selected pitch, the second plurality of parallel scan lines being parallel to the first plurality of parallel scan lines and at positions of the second layer of powder that are offset from the positions of the first plurality of parallel lines by approximately one-half the selected pitch;
and
repeating the dispensing and scanning steps for pluralities of first and second layers of powder to form the article.

3 more elements

An apparatus for fabricating a three-dimensional object, comprising:

a powder delivery system, for applying successive layers of powder;
a laser for generating a laser beam;
a scanning system, for controllably directing the laser beam to a target plane at the surface of a layer of powder;
and
a computer, coupled to the scanning system, and programmed to perform a plurality of operations comprising:
storing, in computer memory, a fill scan spacing value;
and
controlling the scanning system to scan the energy beam in first and second pluralities of parallel scan lines within selected locations of alternating layers of powder corresponding to a cross-section of the article in that layer;
wherein adjacent ones of the first and second pluralities of parallel scan lines are at a selected pitch corresponding to the stored fill scan spacing value, and are at positions defined relative to a coordinate axis of the target plane;
and wherein adjacent ones of the second plurality of parallel scan lines are parallel to the first plurality of parallel scan lines at positions that are offset from the positions of the first plurality of parallel lines by approximately one-half the selected pitch.

7 more elements

Dependencies are inferred from the claim text.

Selective laser sintering with interleaved fill scan

Life of this patent

Selective laser sintering with interleaved fill scan

Life of this patent

Abstract

Claims17