Method and system for producing complex-shape objects

A method for producing three-dimensional, net-shape objects from powdered material, comprising the steps of:

• a) forming a molten region on a growth surface by directing a laser beam thereon;
• b) generating a substantially continuous and uniform flow of a propellant gas and powdered material mixture;
• c) converting said flow into a converging flow by spraying said flow through a plurality of nozzles circumferentially positioned about the laser beam;
• d) incorporating a portion of the powdered material contained in said converging flow into the molten region by positioning the apex of the converging flow proximate to said molten region;
• and,
• e) translating the molten region so as to deposit layers comprising melted and resolidified powdered material so as to form a three-dimensional, net-shape object.

A system for producing three-dimensional objects from powdered material, comprising:

• a) a deposition stage;
• b) a growth surface which moves in accord with the deposition stage;
• c) a laser configured to direct a laser beam onto the growth surface;
• d) a molten region on the growth surface, generated by the action of the laser beam thereon, comprising:
• 1) melted material from the growth surface;
• and,
• 2) powdered material which melts on incorporation into the molten region;
• e) a delivery system, comprising:
• 1) a passageway therethrough whereby said laser beam can be transmitted substantially without attenuation;
• 2) a plurality of nozzles circumferentially positioned about said passageway and aligned so as to produce a converging flow of a propellant gas and powdered material mixture such that the apex of such converging flow is substantially directed at said molten region;
• 3) a manifold which distributes said propellant gas and powdered material mixture to said plurality of nozzles;
• f) a powder feeder supplying the manifold of said delivery system with a substantially continuous and uniform flow of a propellant gas and powdered material mixture;
• and,
• g) means for translating the delivery system relative to the deposition stage and for depositing layers comprising melted and resolidified powdered material so as to form three-dimensional objects.

A method for producing three-dimensional objects from a plurality of powdered materials and their combinations, comprising the steps of:

• a) forming a molten region on a growth surface by directing a laser beam thereon;
• b) generating a plurality of substantially continuous and uniform mixture flows, each said mixture flow comprising a propellant gas and at least one of the plurality of powdered materials;
• c) combining the plurality of substantially continuous and uniform mixture flows into a predetermined master flow, the composition of which is determined by regulating the amount of each of the plurality of substantially continuous and uniform mixture flows that is combined into said master flow;
• d) converting said master flow into a converging flow by spraying said master flow through a plurality of nozzles circumferentially positioned about the laser beam;
• e) incorporating a portion of the mixed powdered materials contained in said converging flow into the molten region by positioning the apex of the converging flow proximate to said molten region;
• and
• f) translating the molten region so as to deposit layers comprising melted and resolidified powdered materials so as to form a three-dimensional object.