Metal powder fusion manufacturing with improved quality
A method of manufacturing a three-dimensional article is provided for a system including a powder handling module containing stored metal powder. The stored metal powder includes used metal powder that was previously part of the metal powder loaded into a print engine during a previous fabrication process. The method includes (1) loading a volume of the metal powder into an agitation device, (2) operating the agitation device until an avalanche angle of the metal powder is modified to within a specified range to provide a volume of usable metal powder, (3) loading the usable metal powder into a three-dimensional print engine, and (4) operating the print engine to fabricate a the three-dimensional article. This process improves coating quality within the print engine. Improving coating quality improves dimensional accuracy of the three-dimensional article along with reducing defects resulting from coating artifacts.
1. A method of manufacturing a three-dimensional article comprising:
(1) operating a three-dimensional printer to form a first three-dimensional article through the selective fusion of layers of metal powder in a build container with a volume of used but unfused metal powder remaining in the build container after the selective fusion of layers;
(2) transporting the used metal powder from the build container to a powder handling module;
(3) operating the powder handling module including storing the used metal powder to provide stored metal powder;
(4) transporting a volume of the stored metal powder to an agitation device;
(5) operating the agitation device to modify an avalanche angle of the metal powder to within a specified range to provide usable metal powder, the avalanche angle is a measurable material property of the metal powder, the specified range is within a range of 1 to 50 degrees;
(6) load the usable metal powder into the three-dimensional printer; and
(7) operate the three-dimensional printer to form a second three-dimensional article.
2. The method of claim 1 wherein the power handling module includes a gas handling system including a source of inert gas and a vacuum source, operating the powder handling module includes transporting the used metal powder through a tube by entraining the metal powder in a flow of the inert gas.
3. The method of claim 1 wherein step (2) includes transporting the used metal powder from the build container to a recovered powder silo within the powder handling module.
4. The method of claim 3 wherein step (3) includes transporting the used metal powder from the recovered powder silo, through a sieve, and to a powder storage silo.
5. The method of claim 4 further comprising transporting new unused metal powder into the powder storage silo.
6. The method of claim 1 wherein agitation device includes one or more of a stirring device, an ultrasonic transducer, and a motorized vibratory device.
7. The method of claim 1 wherein operating the agitation device includes agitating the metal powder for at least three hours.
8. The method of claim 1 further comprising determining the avalanche angle of the volume of metal powder before, during, and/or after step (5).
9. The method of claim 1 , wherein step (6) includes:
loading the agitated metal powder into a removable powder module (RPM); and
loading the RPM into the three-dimensional printer.
10. A method of manufacturing a three-dimensional article comprising:
(1) operating a three-dimensional printer to form a first three-dimensional article through the selective fusion of layers of metal powder in a build container with a volume of used but unfused metal powder remaining in the build container after the selective fusion of layers;
(2) transporting the used metal powder from the build container to a powder handling module;
(3) operating the powder handling module including storing the used metal powder to provide stored metal powder;
(4) transporting a volume of the stored metal powder to an agitation device;
(5) operating the agitation device for at least an hour to reduce an overall range of an avalanche angle of the metal powder, the avalanche angle is a measurable material property of the metal powder, the overall range of the avalanche angle is within a range between 1 and 50 degrees;
(6) load the usable metal powder into the three-dimensional printer; and
(7) operate the three-dimensional printer to form a second three-dimensional article.
11. The method of claim 10 wherein operating the agitation device includes operating the agitation device for more than 5 hours.
12. The method of claim 10 wherein operating the agitation device includes operating the agitation device for more than 10 hours.