Laser-produced porous structure

Abstract

The present invention disclosed a method of producing a three-dimensional porous tissue in-growth structure. The method includes the steps of depositing a first layer of metal powder and scanning the first layer of metal powder with a laser beam to form a portion of a plurality of predetermined unit cells. Depositing at least one additional layer of metal powder onto a previous layer and repeating the step of scanning a laser beam for at least one of the additional layers in order to continuing forming the predetermined unit cells. The method further includes continuing the depositing and scanning steps to form a medical implant.

1 . A method of producing a three-dimensional porous tissue in-growth structure comprising the steps of: 
 depositing a first layer of a powder made from a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium onto a substrate; and    scanning a laser beam having a power (P) for a period of time (μsec) with a point distance (μm), to form a portion of a plurality of predetermined unit cells within said metal powder layer.    
     
     
         2 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , further comprising depositing at least one additional layer of said powder onto said first layer and repeating the step of scanning a laser beam for at least one of said deposited layers in order to continuing forming said predetermined unit cells.  
     
     
         3 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein at least some of said predetermined unit cells are a tetrahedron.  
     
     
         4 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein at least some of said predetermined unit cells are a dodecahedron.  
     
     
         5 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein at least some of said predetermined unit cells are an octahedron.  
     
     
         6 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein at least some of said predetermined unit cells are truncated.  
     
     
         7 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein said first layer of metal powder has a thickness between 5 μm to 2000 μm.  
     
     
         8 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 2 , wherein said at least one additional layer of powder has a thickness between 5 μm to 2000 μm.  
     
     
         9 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 2 , further comprising predetermining a porosity range for at least one deposited powder layer and scanning said at least one deposited powder layer in a manner to provide said deposited powder layer with a porosity within said porosity range.  
     
     
         10 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein said substrate is a base or core made of a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium, wherein said first layer is fused to said base or core.  
     
     
         11 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 10 , further comprising sintering at least a portion of said first powder layer to said base or core.  
     
     
         12 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 10 , wherein said base or core is separated from said first layer.  
     
     
         13 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 12 , wherein said base or core is integral with said first layer and imparts additional physical properties to an overall construct.  
     
     
         14 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein said laser power is in a range between 5 to 1000 watts.  
     
     
         15 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein a solid or a semi-pervious layer is placed between said substrate and said first metal powder layer.  
     
     
         16 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 2 , wherein during the step of scanning said powder layer a plurality of satellites are formed on portions of said predetermined unit cells.  
     
     
         17 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 16 , further comprising an acid etching process to remove said satellites.  
     
     
         18 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein said laser power is 90.5 W, said exposure time is 1000 μsec and said point distance is 90 μm.  
     
     
         19 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 1 , wherein at least some of said predetermined unit cells are truncated to provide a barb effect.  
     
     
         20 . A method of producing a three-dimensional structure comprising the steps of: 
 depositing a first layer of a powder made from a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium onto a substrate;    scanning a laser beam having a power (P) for a period of time (μsec) with a point distance (μm), to form a portion of a plurality of predetermined unit cells within said powder layer, said predetermined unit cells having a plurality of struts with a length and a cross section;    depositing at least one additional layer of said powder onto said first layer; and    repeating the step of scanning a laser beam for at least some of said additional deposited layers in order to continue forming said predetermined unit cells.    
     
     
         21 . The method of producing a three-dimensional structure according to  claim 20 , wherein at least some of said struts have a cross-section which is circular.  
     
     
         22 . The method of producing a three-dimensional structure according to  claim 20 , wherein at least some of said struts have a cross-section which is rectangular.  
     
     
         23 . The method of producing a three-dimensional structure according to  claim 20 , wherein some of said struts intersect at a plurality of intersection points, further comprising sintering at least some of said intersection points.  
     
     
         24 . The method of producing a three-dimensional structure according to  claim 23 , wherein said step of sintering is preformed after most of said scanning and depositing steps are completed.  
     
     
         25 . The method of producing a three-dimensional structure according to  claim 20 , wherein said substrate is a base or core made of a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium, wherein said first layer is fused to said base or core.  
     
     
         26 . The method of producing a three-dimensional structure according to  claim 20 , wherein said substrate is a work platform.  
     
     
         27 . The method of producing a three-dimensional structure according to  claim 20 , wherein during the step of scanning said powder layers, said laser beam is adjusted to modify said length of said struts of said predetermined unit cells.  
     
     
         28 . The method of producing a three-dimensional structure according to  claim 20 , wherein at least some of said predetermined unit cells are deformed so as to drape over said substrate.  
     
     
         29 . The method of producing a three-dimensional structure according to  claim 20 , wherein during the step of scanning said metal powder layers, said laser beam is adjusted to modify said cross-section of said struts of said predetermined unit cells.  
     
     
         30 . The method of producing a three-dimensional structure according to  claim 20 , further comprising employing laser beam compensation.  
     
     
         31 . The method of producing a three-dimensional structure according to  claim 20 , wherein said exposure time is in a range between 100 μsec to 100 μsec.  
     
     
         32 . The method of producing a three-dimensional structure according to  claim 20 , wherein at least some of said predetermined unit cells are off-set from one another to allow at least some struts of said predetermined unit cells to overlap some struts of another predetermined unit cell.  
     
     
         33 . The method of producing a three-dimensional structure according to  claim 20 , wherein at least some of said predetermined unit cells have a coating of unmelted metal particles.  
     
     
         34 . The method of producing a three-dimensional construct, according to  claim 20 , further including an acid etching process.  
     
     
         35 . The method of producing a three-dimensional structure according to  claim 20 , wherein said metal powder layers are deposited and scanned in order to form a medical implant, said medical implant having a porosity which falls within a predetermined porosity range.  
     
     
         36 . A method of producing a three-dimensional construct, the method comprising the steps of: 
 loading a file of a component into an engineering design package;    scaling down the component in said file from its original size within said engineering design package;    constructing a boolean operation within said engineering design package to subtract said original component from said scaled down component to create a jacket;    processing said jacket using a bespoke application that populates said jacket with a repeating open cellular lattice structure;    slicing the complete open cellular lattice jacket using said bespoke program to a predetermined layer thickness;    loading the main body of the file component jacket into a user interface program;    slicing said jacket into layers having a predetermined thickness;    applying hatching to the file component jacket as required to build a solid construct;    merging the file component jacket with said open cellular lattice structure; and    building the final product using the method of  claim 17 .    
     
     
         37 . A method of producing a three-dimensional construct, the method comprising the steps of: 
 providing a file component representation of an object;    depositing a layer of metal powder onto a substrate;    scanning said metal powder with a laser beam to form a portion of a plurality of predetermined unit cells in said metal powder;    depositing additional layers of metal powder successively onto a previous layer, wherein each layer or portion thereof is scanned using said laser beam; and    depositing and scanning said metal layers to form an actual component which resembles of said file component representation.    
     
     
         38 . A method of producing a three-dimensional porous tissue in-growth structure comprising the steps of: 
 depositing a first layer of a powder made from a metal selected from the group consisting of titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium onto a work platform    scanning said first layer of metal powder with a laser beam having a power (P) for a period of time (μsec) with a point distance (μm) to form a portion of a plurality of predetermined unit cells within said metal powder layer.    
     
     
         39 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 38 , further comprising depositing at least one additional layer of said powder onto said first layer and repeating the step of scanning a laser beam for each deposited layer in order to continue forming said predetermined unit cells.  
     
     
         40 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 39 , wherein at least some of said predetermined unit cells are regular unit cells.  
     
     
         41 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 39 , wherein at least some of said predetermined unit cells are irregular unit cells.  
     
     
         42 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 39 , further comprising prior to scanning said powder layer, predetermining a range of porosity for said metal powder layer and adjusting said laser beam so that said laser beams scans said metal powder layer to produce a layer of melted powder having a porosity within said predetermined range.  
     
     
         43 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 42 , wherein said laser beam is adjusted for scanning more than one powder layer without having to be adjusted again.  
     
     
         44 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 42 , wherein said powder layers are deposited and scanned in a manner to form a medical implant.  
     
     
         45 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , wherein said medical implant is an acetabular shell.  
     
     
         46 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 45 , further comprising providing an acetabular cup, wherein said acetabular shell includes a rim, said rim adapted for allowing said acetabular shell to be snap-fitted to said acetabular cup.  
     
     
         47 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 45 , furthering comprising providing an acetabular cup, sintering said acetabular shell to said acetabular cup.  
     
     
         48 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , further comprising providing a base or core, sintering said medical implant to said base or core.  
     
     
         49 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 48 , wherein said base or core is produced using the method of  claim 39 .  
     
     
         50 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , further comprising varying said porosity throughout said medical implant in order to provide bone in-growth characteristics to said medical implant.  
     
     
         51 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , further comprising varying said porosity throughout said medical implant to provide soft-tissue characteristics to said medical implant.  
     
     
         52 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , further comprising providing a base or core, mapping at least some of said metal powder layers to said base or core.  
     
     
         53 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 39 , wherein said metal powder layers are deposited and scanned to create struts, said struts being parts of said predetermined unit cells.  
     
     
         54 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 53 , wherein at least some of said struts have a plurality of satellites.  
     
     
         55 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 54 , further comprising treating said struts with an acid etching treatment to remove said satellites.  
     
     
         56 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 53 , wherein said struts having a cross-section with a plurality of dimensions, further comprising treating said struts with an acid etching treatment to reduce said dimensions of said struts.  
     
     
         57 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , further comprising subjecting said medical implant to a hot isostatic pressing.  
     
     
         58 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , wherein said medical implant is a knee implant.  
     
     
         59 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 44 , wherein said medical implant is a hip implant.  
     
     
         60 . A method of producing a three-dimensional porous tissue in-growth structure comprising the steps of: 
 depositing a first layer of metal powder;    scanning said first layer of metal powder with a laser beam to form a portion of a plurality of predetermined unit cells;    depositing at least one additional layer of said metal powder onto a previous layer and repeating the step of scanning a laser beam for at least one of said additional layers in order to continuing forming said predetermined unit cells; and    continuing said depositing and scanning steps to form a medical implant.    
     
     
         61 . The method of producing a three-dimensional porous tissue in-growth structure according to  claim 60 , wherein said medical implant has a porosity within a predetermined range.