Surface modified unit cell lattice structures for optimized secure freeform fabrication

Patent metadata

Field	Value
Publication number	US-10614176-B2
Application number	US-201514877548-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Apr 6, 2012
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

Aspects of the present disclosure relate generally to preparing models of three-dimensional structures. In particular, a model of a three-dimensional structure constructed of porous geometries is prepared. A component file including a porous CAD volume having a boundary is prepared. A space including the porous CAD volume is populated with unit cells. The unit cells are populated with porous geometries having a plurality of struts having nodes on each end. The space is populated with at least one elongated fixation element extending beyond the boundary to produce an interlocking feature enabling assembly or engagement with a mating structure.

First claim

The invention claimed is:

1. A method of preparing an output file, for use by an additive layer manufacturing machine, of a computer-generated model of a three-dimensional structure constructed of porous geometries, the method comprising:
preparing a computer-generated component file including a porous CAD volume having a boundary;
populating, by a processor, a space including the porous CAD volume with unit cells on or overlapping the boundary;
populating, by the processor, the unit cells with porous geometries, the porous geometries having a plurality of struts having opposing ends, each end being connected at a corresponding node, the plurality of struts including at least a first strut intersecting the boundary and having a length, one end connected at a first node at a first location either (i) on the boundary or (ii) outside the porous CAD volume, and another end connected at a second node at a second location either (i) on the boundary or inside the porous CAD volume when the first node is outside the porous CAD volume or (ii) inside the porous CAD volume when the first node is on the boundary, the length of the first strut being defined between the first and the second nodes;
removing, by the processor, only all struts entirely outside the boundary of the porous CAD volume such that each end of the remaining struts remains connected at its corresponding node;
moving, by the processor, either (i) the first node of the first strut from the first location to a third location along the boundary in creating the computer-generated model of the three-dimensional structure or (ii) the second node of the first strut from the second location to a fourth location along the boundary in creating the computer-generated model of the three-dimensional structure;
storing the computer-generated model of the three-dimensional structure into an output file usable by an additive layer manufacturing machine in preparing the three-dimensional structure;
depositing a first layer of metal powder onto a substrate;
scanning a beam at predetermined locations of the deposited first layer of the metal powder to form a first layer of the three-dimensional structure;
depositing successive layers of the metal powder onto the first layer of the three-dimensional structure; and
scanning, respectively, each of the successive deposited layers of the metal powder with the beam at predetermined locations of the successive deposited layers to form additional layers of the three-dimensional structure, the three-dimensional structure having a geometric lattice structure corresponding to the form of the computer-generated model, the geometric lattice structure constructed of formed porous geometries corresponding to the porous geometries populating the unit cells of the computer-generated model.

2. The method of producing a three-dimensional structure according to claim 1 , wherein the beam is an electron beam or a laser beam.

3. A method of preparing an output file, for use by an additive layer manufacturing machine, of a computer-generated model of a three-dimensional structure constructed of formed porous geometries and a formed surface with a formed first strut supported at opposing ends thereof, the method comprising:
preparing a computer-generated component file including a porous CAD volume having a boundary;
populating, by a processor, a space including the porous CAD volume with unit cells on or overlapping the boundary;
populating, by the processor, the unit cells with porous geometries, the porous geometries having a plurality of struts having opposing ends, each end being connected at a corresponding node, the plurality of struts including at least a first strut intersecting the boundary and having a length, one end connected at a first node at a first location either (i) on the boundary or (ii) outside the porous CAD volume, and another end connected at a second node at a second location either (i) on the boundary or inside the porous CAD volume when the first node is outside the porous CAD volume or (ii) inside the porous CAD volume when the first node is on the boundary, the length of the first strut being defined between the first and the second nodes;
removing, by the processor, only all struts entirely outside the boundary of the porous CAD volume such that each end of the remaining struts remains connected at its corresponding node;
replacing, by the processor, either (i) the first node with a first replacement node at a third location along the boundary in creating a modified first strut corresponding to the formed first strut or (ii) the second node with a second replacement node at a fourth location along the boundary in creating the modified first strut such that the opposing ends of the modified first strut are connected to respective other struts;
generating the computer-generated model of the three-dimensional structure configured for additive layer manufacturing, the computer-generated model having unmodified porous geometries of the porous geometries populating the unit cells that correspond to the formed porous geometries and having a computer-generated surface corresponding to the formed surface that includes one of the opposing ends of the formed first strut without clipping the first strut; and
storing the computer-generated model of the three-dimensional structure into an output file usable by an additive layer manufacturing machine in preparing the three-dimensional structure.

4. The method of claim 3 , at least one adjacent strut adjacent to the first strut and inside the porous CAD volume being connected at the second node, wherein a closer of the first node or the second node to the boundary is replaced by the respective one of the first replacement node and second replacement node along the boundary.

5. The method of claim 4 , further comprising:
when the first node is the closer node to the boundary, replacing, by the processor, the first strut with a first replacement strut connected at the first replacement node and to the at least one adjacent strut; and
when the second node is the closer node to the boundary, replacing, by the processor, the adjacent strut with a replacement adjacent strut connected at the second replacement node.

6. A method of preparing an output file, for use by an additive layer manufacturing machine, of a computer-generated model of a three-dimensional structure constructed of formed porous geometries and a formed surface with a formed first strut supported at opposing ends thereof, the method comprising:
preparing a computer-generated component file including a porous CAD volume having a boundary;
populating, by a processor, a space including the porous CAD volume with unit cells on or overlapping the boundary;
populating, by the processor, the unit cells with porous geometries, the porous geometries having a plurality of struts having opposing ends, each end being connected at a corresponding node, the plurality of struts including at least a first strut intersecting the boundary and having a length, one end connected at a first node at a first location either (i) on the boundary or (ii) outside the porous CAD volume, and another end connected at a second node at a second location either (i) on the boundary or inside the porous CAD volume when the first node is outside the porous CAD volume or (ii) inside the porous CAD volume when the first node is on the boundary, the length of the first strut being defined between the first and the second nodes;
removing, by the processor, only all struts entirely outside the boundary of the porous CAD volume such that each end of the remaining struts remains connected at its corresponding node;
moving, by the processor, either (i) the first node of the first strut from the first location to a third location along th

Assignees

• Howmedica Osteonics Corp
• Univ Liverpool

Inventors

• Dong Nicholas Nai Guang
• Poggie Matthew P
• Klein Robert W
• Jones Eric
• Sutcliffe Christopher J
• Robinson Joe
• Jones Dan
• Mullen Lewis
• Stamp Robin

Classifications

• G06F30/00

  Computer-aided design [CAD] · CPC title

• B23K15/0086

  welding for purposes other than joining, e.g. build-up welding · CPC title

• A61F2/30942 Primary

  for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• A61F2002/30952

  using CAD-CAM techniques or NC-techniques · CPC title