Multilayer parameter-varying fusion and deposition strategies for additive manufacturing
The invention encompasses compositions and methods for designing or producing three-dimensional articles layer-by-layer, whereby the specific approach to build-up a region of a single layer by fusion, deposition of material, or other path-based process or non-path process that creates track-like geometries requires either differing track or track-like geometry, or track or track-like geometry printing parameters, within a region of a single layer or within adjoining regions of multiple layers, is disclosed. Employing this method, single layer or multilayer parameter-varying fusing and deposition strategies can be generated that reduce article fabrication time and improve article physical properties, in part by targeting a distribution of scan paths that satisfy covering problem overlap and/or dense packing criteria. Additionally, methods and compositions for designing or producing three-dimensional articles by altering the thickness of a material layer deposited during a print relative to the slice thickness or net displacement of a stage or of a material and/or energy-depositing print head, are disclosed. Employing this method can result in the reduction of article fabrication time and/or the improvement of printed article physical properties, where these results advantageous to printing are dependent on the print process, material properties, and feedstock properties employed during the print.
1. An additively manufactured composition, printed using a scan or track based process, or any additive manufacturing process generating layers with surface geometry similar to that produced by any scan or track based process, where within a region of a printed article:
a. tracks or track cross sections exhibit a plurality of geometries (shapes and/or sizes), either within a single layer contained within the region or across a plurality of successive layers,
b. configurations of the tracks or track cross sections can be characterized by a unit cell, described on an average across tracks or track cross sections in Euclidean or other geometric space, with a basis of no less than two,
c. the tracks printed within the unit cell are connected within the unit cell in a sense that there is no connected area (volume) of unprinted material or space within the unit cell larger than an area (volume) of the largest track cross section (track), and
d. where portions of or all of at least two adjacent unit cells are present in each layer that is partially or entirely contained within the region.
2. The composition of claim 1 , where within a region of the printed article, the configurations and average geometries of tracks or track cross sections form a covering problem solution or near-solution including a plurality of unit cells within a portion of each layer contained within the region.
3. The composition of claim 1 , wherein track geometry or track cross sections are all or nearly all substantially similar to one another within a region of a layer n, and where in an adjoining region of the plurality of successive layers n+1, track geometry or track cross sections are also all or nearly all substantially similar to one another, but different from those in layer n.
4. The composition of claim 1 , wherein a plurality of track geometries or track cross sections are employed within a region of or all of at least one layer, and where these track geometries or track cross sections differ in a coordinated fashion within the regions of the at least one layer which they are employed.
5. The composition of claim 1 , wherein the tracks are all parallel or anti-parallel.
6. The composition of claim 1 , wherein the tracks in a region of a given layer are rotated by non-zero angle relative to those in a prior layer.
7. The composition of claim 1 , wherein the tracks in a region of a given layer or layers follow one or more non-straight contours.
8. The composition of claim 1 , wherein the layers on which the tracks in a region of an article are printed are non-planar.
9. The composition of claim 1 , wherein an order of printing of tracks within a region of a layer or layers is such that either adjacent tracks or non-adjacent tracks are printed successively.
10. The composition of claim 9 , wherein the order of printing is such that all tracks of one geometry are printed, then tracks of a different geometry are printed.
11. The composition of claim 2 , wherein the plurality of geometries (size and/or shape), and/or the configuration of the tracks printed is non-periodic or quasicrystalline.