Blue Laser Metal Additive Manufacturing System

Abstract

A high-resolution additive manufacturing system based on a parallel printing method using a spatial light modulator. A method and system for additive manufacturing using a DMD in the laser beam path. The use of a pre-heat laser beam in combination with a build laser beam having a DMD along the build laser beam path.

1 - 124 . (canceled) 
     
     
         125 . An additive manufacturing system for metals comprising: a laser; a spatial light modulator in optical communication with the laser; wherein the spatial light modulator is configured to form a pattern on a powder metal layer that is fused to the layer below; a gantry system to step and repeat an image across the powder metal layer; a motion control system; an elevator to displace a part down after the powder metal layer is fused; a powder distribution system that can both spread the powder and compact it before fusing; a controlled atmosphere build chamber; and a means for cooling the spatial light modulator. 
     
     
         126 . The system of  claim 125 , wherein the laser provides a laser beam having a wavelength selected from the group consisting of blue wavelengths and green wavelengths. 
     
     
         127 . The system of  claim 126 , wherein the laser has a power from about 1 kW to about 20 kW; and the pattern on the powder metal layer has a peak power density of from about 2 kW/cm 2  to about 5 kW/cm 2 . 
     
     
         128 . The system of  claim 127 , wherein the laser has a bandwidth selected from the group consisting of about 5 nm, about 10 nm and about 20 nm. 
     
     
         129 . The system of  claim 125 , comprising a beam dump. 
     
     
         130 . The system of  claim 125 , comprising a means to provide a gray scale pattern. 
     
     
         131 . An additive manufacturing system for forming metal objects from metal powders, the system comprising:
 a. a laser source to provide a build laser beam along a build laser beam path;   b. a means for heating a layer of a metal powder;   c. a digital micro-mirror device (DMD) having an average rated power density;   d. the DMD on the build laser beam path; whereby the build laser beam is directed onto the DMD, wherein the DMD is configured to create a 2-D image pattern that is reflected from the DMD along the build laser beam path to an optical assembly;   e. the optical assembly configured to direct the 2-D image pattern to a surface of a layer of metal powder; wherein the 2-D image pattern has a peak power density at the surface of the layer of metal powder;   f. wherein the peak power density is greater than the average rated power density for the DMD.   
     
     
         132 . The system of  claim 131 , wherein the means for heating is selected from the group consisting of an electric heater, a radiant heater, an IR heater and a laser beam. 
     
     
         133 . The system of  claim 132 , comprising an homogenizer on the build laser beam path positioned between the laser source and the DMD. 
     
     
         134 . The system of  claim 131 , wherein the peak power density is at least 500× greater than a maximum average rated power density of the DMD. 
     
     
         135 . The systems of  claims 131 , comprising a means to provide a gray scale pattern. 
     
     
         136 . The system of  claim 131 , comprising a beam dump in optical communication with the DMD. 
     
     
         137 . The system of  claim 131 , wherein the DMD is cooled. 
     
     
         138 . The system of  claim 137 , wherein the DMD is cooled by a means selected from the group consisting of air cooled, water cooled, micro-channel cooler, and a Peltier cooler. 
     
     
         139 . The system of  claim 132 , wherein the metal powder forms a bed of metal powder. 
     
     
         140 . The system of  claim 132 , wherein the laser beam has a wave length select from the group consisting of blue and green. 
     
     
         141 . The system of  claim 132 , wherein the laser beam has a wavelength selected from the group consisting of about 450 nm, about 460 nm, about 515 nm, about 532 nm and about 550 nm. 
     
     
         142 . The system of  claim 132 , wherein the laser source has a power of about 150 W to about 20 kW. 
     
     
         143 . The system of  claim 132 , wherein the peak power density is from about 2 kW/cm 2  to about 5 kW/cm 2 . 
     
     
         144 . The system of  claim 132 , wherein the system has a resolution of about 0.5 μm to about 10 μm. 
     
     
         145 . An additive manufacturing system for forming metal objects from metal powders, the system comprising:
 a. a laser source to provide a laser beam along a laser beam path;   b. a digital micro-mirror device (DMD) having an average rated power density;   c. the DMD on the laser beam path; whereby the laser beam is directed onto the DMD, wherein the DMD is configured to create a 2-D image pattern that is reflected from the DMD along the laser beam path to a surface of a bed of metal powder; and,   d. the 2-D image having a wavelength and a power density; whereby the 2-D image is configured to conduction mode weld the bed of metal powder.   
     
     
         146 . The system of  claim 145 , wherein a peak power density of the 2-D image is from about 2 kW/cm 2  to about 5 kW/cm 2 . 
     
     
         147 . The system of  claim 146 , wherein a peak power density of the 2-D image is at least from 10× to 1000× greater than an average rated power density for the DMD. 
     
     
         148 . The system of  claim 146 , wherein a peak power density level of the 2-D image on the metal powder is at least 500× greater than a maximum average power density level of the DMD 
     
     
         149 . The system of  claim 148 , comprising a means for cooling the DMD. 
     
     
         150 . The system of  claim 149 , wherein the wavelength is selected from the group consisting of blue and green. 
     
     
         151 . The system of  claim 150 , wherein the metal powder comprises a material selected from the group consisting of brass, brass alloys, titanium, titanium alloys, steel, steel alloys, stainless steel, stainless steel alloys, nickel, nickel alloys, gold, gold alloys, silver, silver alloys, platinum, platinum alloys, copper, copper alloys, anodized aluminum, anodized aluminum alloys, aluminum and aluminum alloys. 
     
     
         152 . The system of  claim 151 , wherein the conduction mode weld is spherical. 
     
     
         153 . The system of  claim 150 , wherein the laser beam has a wavelength selected from the group consisting of about 450 nm, about 460 nm, about 515 nm, about 532 nm and about 550 nm. 
     
     
         154 . An additive manufacturing system for forming metal objects from metal powders, the system comprising:
 a. a laser source to provide a build laser beam along a build laser beam path; wherein the build laser beam has a wavelength selected from the group consisting of blue and green;   b. an homogenizer on the build laser beam path;   c. a digital micro-mirror device (DMD) on the build laser beam path;   d. a means for cooling the DMD;   e. a beam dump;   f. whereby the DMD is configured to create a 2-D image pattern on a surface layer of a metal powder;   g. whereby the 2-D image pattern has a sufficient power density to fuse the surface layer of the metal powder to a layer below the surface layer; and,   h. wherein the metal powder comprises a material selected from the group consisting of brass, brass alloys, titanium, titanium alloys, steel, steel alloys, stainless steel, stainless steel alloys, nickel, nickel alloys, gold, gold alloys, silver, silver alloys, platinum, platinum alloys, copper, copper alloys, anodized aluminum, anodized aluminum alloys, aluminum and aluminum alloys.