US 5,837,960 AGranted

Laser production of articles from powders

AssigneeThe Regents of the University of California

InventorsGary K. Lewis, John O. Milewski, David A. Cremers, Ronald B. Nemec, Michael R. Barbe

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Abstract

Method and apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. Preferably the tool path and other parameters of the deposition process are established using computer-aided design and manufacturing techniques. A controller comprised of a digital computer directs movement of a deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which a deposition head which delivers the laser beam and powder to the deposition zone moves along the tool path.

Claims30

Dependent claims

A method of forming an article from materials in particulate form, said method comprising:

a. defining shape and dimensions of an article and creating a tool path and control commands effective to form said article by deposition of molten material;
b. focusing a laser beam at a location within a deposition zone;
c. providing powder to said deposition zone along a plurality of paths which are disposed about the laser beam and converge within the deposition zone;
d. forming a pool of molten material in the deposition zone by melting a portion of an article support and said powder by means of energy provided by said laser beam;
e. depositing molten material from the deposition zone on said article support at points along a first portion of said tool path by moving the deposition zone along the tool path, where said molten material solidifies after leaving the deposition zone, in order to form a portion of said article which is adjacent to the article support;
f. forming a pool of molten material in the deposition zone by melting a portion of said partially formed article and said powder by means of energy provided by the laser beam;
g. depositing molten material from the deposition zone at points along a second portion of the tool path by moving the deposition zone along the tool path, where the molten material solidifies after leaving the deposition zone, in order to complete formation of the article;
and
h. controlling flow of powder into the deposition zone, energy density of the laser beam, and speed of movement of the deposition zone along the tool path by means of said control commands as deposition takes place.

6 more elements

Apparatus for forming an article from materials in particulate form comprising:

a. means for defining shape and dimensions of an article and creating a tool path and control commands which are effective to form said article by deposition of molten material;
b. means for storing said tool path and control commands;
c. means for providing a laser beam and focusing said laser beam at a location within a deposition zone, where said laser beam is capable of providing sufficient energy to substantially melt material in said deposition zone;
d. a delivery nozzle comprised of a laser beam passage through which the laser beam passes and a plurality of passages for flow of powder carried by a gas stream, where said powder passages are disposed around said beam passage and their extended axial center-lines converge in the deposition zone;
e. means for providing powder to said delivery nozzle;
f. means for moving the deposition zone along said tool path;
g. means for controlling movement of the deposition zone in accordance with said stored tool path;
and
h. means for controlling rate of flow of powder into the deposition zone, energy density of the laser beam, and speed of movement of the deposition zone along the tool path in accordance with said stored control commands.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/566,430Filed 30 Nov 1995
Granted: 17 Nov 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

B23K 26/1476
Supply to, or discharge from, nozzles of media, e.g. gas, powder, wire: features inside the nozzle for feeding the fluid stream through the nozzle
B23K 26/144
Using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor: the fluid stream containing particles, e.g. powder
B23K 26/32
Bonding: taking account of the properties of the material involved
B23K 26/34
Working by laser beam, e.g. welding, cutting or boring: laser welding for purposes other than joining