ELECTRON BEAM LAYER MANUFACTURING

摘要

A process and apparatus for free form fabrication of a three-dimensional work piece comprising (a) feeding raw material in a solid state to a first predetermined location; (b) depositing the raw material onto a substrate as a molten pool deposit under a first processing condition; (c) monitoring the molten pool deposit for a preselected condition; (d) comparing information about the preselected condition of the monitored molten pool deposit with a predetermined desired value for the preselected condition of the monitored molten pool deposit; (e) solidifying the molten pool deposit; (f) automatically altering the first processing condition to a different processing condition based upon information obtained from the comparing step (d); and repeating steps (a) through (f) at one or more second locations for building up layer by layer a three-dimensional work piece. The apparatus is characterized by a detector that monitors a preselected condition of the deposited material and a closed loop electronic control device for controlling operation of one or more components of the apparatus in response to a detected condition by the detector.

主权项

1. An apparatus for layer manufacturing a metallic three-dimensional work piece, comprising:
a) a housing defining a chamber capable of evacuation and within which the metallic three-dimensional work piece is formed layer by layer from a plurality of successively deposited molten pool deposits, the housing enclosing:
A. a plurality of wires fed from one or more material delivery devices;B. an electron beam gun that melts the plurality of wires;C. a table upon which the metallic three-dimensional work piece is formed, the table and the electron beam gun being adjustably spaced relative to each other so that as the metallic three-dimensional work piece is formed layer by layer from the plurality of successively deposited molten pool deposits, the spacing incrementally increases;D. an optical assembly including:
i. a first enclosure,ii. optics housed in the first enclosure,iii. an aperture in a wall of the first enclosure for allowing access, into the first enclosure, of light emitted by the plurality of successively deposited molten pool deposits so that the light reaches the optics, andiv. a vapor protection device that substantially avoids build-up of metal vapor on the optics during operating of the apparatus;E. an imaging device including:
i. a detector array,ii. thermally regulated electronic componentry, andiii. a second enclosure that substantially encloses the detector array and the thermally regulated electronic componentry, and also includes an opening through which light that is emitted by the plurality of successively deposited molten pool deposits and can communicate with the detector array; andF. a frame that carries the enclosures of the optical assembly and the imaging device in spaced apart relation from each other so that the aperture of first enclosure is substantially overhead of the plurality of successively deposited molten pool deposits, and the first and second enclosures are separated from each other; b) a closed loop control device configured to automatically adjust one or more processing parameters of the apparatus in response to data obtained from the imaging device.