Additive manufacture of turbine component with multiple materials

Abstract

A method for additive manufacturing with multiple materials. First ( 48 ), second ( 50 ), and third ( 52 ) adjacent powder layers are delivered onto a working surface ( 54 A) in respective first ( 73 ), second ( 74 ), and third ( 75 ) area shapes of adjacent final materials ( 30, 44, 45 ) in a given section plane of a component ( 20 ). The first powder may be a structural metal delivered in the sectional shape of an airfoil substrate ( 30 ). The second powder may be a bond coat material delivered in a sectional shape of a bond coat ( 45 ) on the substrate. The third powder may be a thermal barrier ceramic delivered in a section shape of the thermal barrier coating ( 44 ). A particular laser intensity ( 69 A, 69 B) is applied to each layer to melt or to sinter the layer. Integrated interfaces ( 57, 77, 80 ) may be formed between adjacent layers by gradient material overlap and/or interleaving projections.

The invention claimed is: 
     
         1 . A method for making a component, comprising the steps of:
 delivering a plurality of adjacent powder layers of respectively different powder materials onto a working surface in respective area shapes representing respective final materials in a given section plane of a multi-material component;   overlapping at least two of the adjacent powder layers to form a material gradient zone between said at least two adjacent powder layers;   applying a first laser energy of a first intensity to a first of the powder layers, and a second laser energy of a second different laser intensity to a second of the powder layers; and   repeating from the delivering step for successive section planes of the component to fabricate the component.   
     
     
         2 . The method of  claim 1 , wherein the first powder layer comprises a metal, the second powder comprises a thermal barrier ceramic, the first laser energy is directed to follow a first plurality of scan paths parallel to a non-linear perimeter of the first powder layer, and the second laser energy is directed to follow a second plurality of scan paths parallel to a non-linear perimeter of the second powder layer. 
     
     
         3 . The method of  claim 2 , further comprising cycling the first and second laser energies on and off while following the first and second scan paths to form channels passing through the first and second final materials. 
     
     
         4 . The method of  claim 2 , further comprising cycling the second laser energy on and off while following second scan paths to form strain-relief fissures in the second final material. 
     
     
         5 . The method of  claim 1 , further comprising forming a mechanically interlocking interface between the first and second final materials by delivering the first and second powder materials onto the working surface with interleaved profiles there between, forming interleaved fingers across the interface. 
     
     
         6 . The method of  claim 1 , further comprising depositing the first and second powder layers onto the working surface in respective first and second thicknesses, and predetermining the respective laser energies to reduce the powder layers to a uniform thickness of the final materials in the given section plane. 
     
     
         7 . The method of  claim 1 , further comprising providing the first and second laser energies by a laser beam directed along successive linear scan paths that each pass over the first and second powder layers, and further comprising varying the intensities of the laser beam along each scan path to provide the first and second intensities. 
     
     
         8 . A product formed by the method of  claim 1 . 
     
     
         9 . A method of making a component, comprising the steps of:
 delivering respective powders of first, second, and third adjacent layers of respectively different materials onto a working surface in respective first, second, and third area shapes, which in combination represent a given multi-material section plane of the component;   wherein the first powder layer comprises a structural metal material, the second powder layer comprises a bond coat material, and the third powder layer comprises a thermal barrier ceramic;   applying a particular laser energy to each of the powder layers to melt or sinter the layer, wherein at least two of the layers receive respectively different laser intensities; and   repeating from the delivery step with successive section planes to fabricate the component by selective layer additive manufacturing.   
     
     
         10 . The method of  claim 9 , further comprising cycling the laser energies on and off while following scan paths parallel to respective profiles of the area shapes to form channels in the component. 
     
     
         11 . The method of  claim 9 , further comprising directing a first laser energy to follow scan paths parallel to a profile of the first shape, directing a second laser energy to scan paths parallel to a profile of the second shape, and directing a third laser energy to follow scan paths parallel to a profile of the third shape. 
     
     
         12 . The method of  claim 11 , further comprising cycling the third laser energy on and off to form strain-relief fissures in the thermal barrier ceramic. 
     
     
         13 . The method of  claim 11 , further comprising forming a mechanically interlocking interface between the second and third layers by delivering the second and third powders onto the working surface with interleaved profiles there between, forming interleaved fingers in the interface. 
     
     
         14 . The method of  claim 9 , further comprising overlapping the first and second powders by at least 0.2 mm, forming a gradient material zone. 
     
     
         15 . The method of  claim 11 , further comprising overlapping the second and third powders by at least 0.4 mm, forming a gradient material zone. 
     
     
         16 . The method of  claim 11 , further comprising depositing the first and third layers onto the working surface in respective first and second different thicknesses, and predetermining the respective intensities of the laser energies to reduce the three powder layers to a uniform material thickness. 
     
     
         17 . The method of  claim 11 , further comprising providing the first, second, and third laser energies by a laser beam directed along successive lines that each pass over the first, second, and third layers, and further comprising varying an intensity of the laser beam along each line to provide the particular energy for each powder layer crossed by the line. 
     
     
         18 . A method of making a gas turbine component: comprising the steps of:
 delivering first, second, and third adjacent powder layers onto a working surface in respective first, second, and third area shapes of first, second, and third adjacent final materials in a given section plane of the component;   wherein the first material comprises a structural metal, the second material comprises a bond coat metal, and the third material comprises a thermal barrier ceramic;   melting the first and second powder layers with respective first and second laser energies, and only partly melting the third powder layer with a third laser energy, wherein solidification forms a new working surface of the adjacent final materials; and   repeating from the delivery step for successive section planes to fabricate the component of the structural metal with a porous ceramic thermal barrier layer;   wherein the first laser energy is directed to follow a contour of the first shape, the second laser energy is directed to follow a contour of the second shape, and the third laser energy is directed to follow a contour of the third shape.   
     
     
         19 . The method of  claim 18 , further comprising:
 overlapping the first and second powders by at least 0.2 mm, forming a gradient material interface between the first and second layers; and   forming a mechanically interlocking interface between the second and third layers by delivering the second and third powders onto the working surface with interleaved profiles there between, forming interleaved fingers across the interface.   
     
     
         20 . A product formed by the method of  claim 19 .