Laser fabrication of ceramic parts

Abstract

A method of fabricating ceramic parts is disclosed using a laser deposition process to produce highly dense ceramic parts. A metal substrate is preferably used and ceramic powder deposited in layers on the substrate, while varying the power of the laser beam to bond the layers together without cracking the substrate or causing a plasma reaction in the ceramic powder. Dense structures which are about 96% to about 100% ceramic can be produced. A part can be graded using different types and mixtures of ceramic powders to produce the part of a desired composition.

What is claimed is:  
     
         1 . A method of constructing a ceramic part having a high density, the method comprising the steps of: 
 providing a substrate made of a metal, a metal alloy, or a ceramic;    depositing a ceramic powder on the substrate;    directing a laser at the substrate to heat the substrate and melt the powder during the depositing step, thereby shaping the powder as the laser follows a predetermined pattern over the powder and substrate; and    varying the power of the laser during the directing step to allow sufficient melting to form a highly dense structure.    
     
     
         2 . The method of  claim 1 , wherein the highly dense structure is formed substantially without cracking or a plasma reaction in the powder.  
     
     
         3 . The method of  claim 1 , and further comprising repeating the depositing step to form multiple layers from the ceramic powder.  
     
     
         4 . The method of  claim 1 , wherein the density of the ceramic part is from about 90% to about 100% dense.  
     
     
         5 . The method of  claim 1 , wherein the density of the ceramic part is from about 96% to about 100% dense.  
     
     
         6 . The method of  claim 1 , wherein the ceramic powder comprises an oxide or a non-oxide ceramic powder.  
     
     
         7 . The method of  claim 1 , wherein the ceramic powder comprises Al 2 O 3 .  
     
     
         8 . The method of  claim 1 , wherein the ceramic powder comprises AlN.  
     
     
         9 . The method of  claim 1 , wherein the substrate includes Ti-6Al-4V.  
     
     
         10 . The method of  claim 1 , wherein the step of varying the power is performed over a power range of about 30 W to about 550 W.  
     
     
         11 . The method of  claim 1 , wherein the step of varying the power is performed over a power range of about 30 W to about 150 W.  
     
     
         12 . The method of  claim 1 , wherein the step of varying the power comprises reducing the laser power from about 150 W to about 60 W.  
     
     
         13 . The method of  claim 1 , wherein the depositing step further comprises separately feeding first and second types of ceramic particles.  
     
     
         14 . The method of  claim 13 , wherein the depositing step further comprises selectively forming layers of the first and second types of ceramic particles on the part.  
     
     
         15 . An article of manufacture comprising a ceramic part having a high density obtainable by a method comprising the steps of: 
 providing a substrate made of a metal, a metal alloy, or a ceramic;    depositing a ceramic powder on the substrate;    directing a laser at the substrate to heat the substrate and melt the powder during the depositing step, thereby shaping the powder as the laser follows a predetermined pattern over the powder and substrate; and    varying the power of the laser during the directing step to allow sufficient melting to form the highly dense ceramic part.    
     
     
         16 . The article of  claim 15 , wherein the highly dense part is formed substantially without cracking or a plasma reaction in the powder.  
     
     
         17 . The article of  claim 15 , and further comprising repeating the depositing step to form multiple layers from the ceramic powder.  
     
     
         18 . The article of  claim 15 , wherein the ceramic part is from about 90% to about 100% dense.  
     
     
         19 . The article of  claim 15 , wherein the density of the ceramic part is from about 96% to about 100% dense.  
     
     
         20 . The article of  claim 15 , wherein the ceramic powder comprises an oxide or a non-oxide ceramic powder.  
     
     
         21 . The article of  claim 15 , wherein the ceramic powder comprises Al 2 O 3 .  
     
     
         22 . The article of  claim 15 , wherein the ceramic powder comprises AlN.  
     
     
         23 . The article of  claim 15 , wherein the substrate includes Ti-6Al-4V.  
     
     
         24 . The article of  claim 15 , wherein the step of varying the power is performed over a power range of about 30 W to about 550 W.  
     
     
         25 . The article of  claim 15 , wherein the step of varying the power is performed over a power range of about 30 W to about 150 W.  
     
     
         26 . The article of  claim 15 , wherein the step of varying the power comprises reducing the laser power from about 150 W to about 60 W.  
     
     
         27 . The article of  claim 15 , wherein the depositing step further comprises separately feeding first and second types of ceramic particles.  
     
     
         28 . The article of  claim 27 , wherein the depositing step further comprises selectively forming layers of the first and second types of ceramic particles on the part.  
     
     
         29 . A method of constructing a ceramic part having a high density, the method comprising the steps of: 
 providing a substrate made of a metal, a metal alloy, or a ceramic;    depositing a ceramic powder on the substrate in a first layer;    directing a laser at the substrate to heat and melt the ceramic powder during the depositing step, thereby shaping the powder as the laser follows a predetermined pattern over the powder and substrate;    varying the power of the laser during the directing step to allow sufficient melting to form a highly dense structure; and    forming at least one additional layer by depositing ceramic powder on the first layer.    
     
     
         30 . The method of  claim 29 , wherein the highly dense part is formed substantially without cracking or a plasma reaction in the powder.  
     
     
         31 . The article of  claim 29 , wherein the ceramic part is from about 90% to about 100% dense.  
     
     
         32 . The article of  claim 29 , wherein the density of the ceramic part is from about 96% to about 100% dense.