Patent ID: 8461474

Claim:
A method for layer-by-layer manufacturing of a three-dimensional metallic work piece, comprising the steps of: a) delivering a metallic feed material in a substantially solid state into a feed region; b) emitting an electron beam having one or more predetermined electrical currents; c) translating the electron beam through a first predetermined raster pattern frame in an, x-y plane that includes: (i) a plurality of points within the feed region sufficient so that the metallic feed material is subjected to a melting beam power density level sufficient to cause melting of the metallic feed material and formation of a molten pool deposit; and (ii) a plurality of points in a substrate region that is outside of the feed region, sufficient so that the plurality of points outside the feed region is subjected to a substrate beam power density level that is different from the melting beam power density level; d) monitoring a condition of one or both of the feed region or the substrate region substantially in real time for the occurrence of any deviation from a predetermined condition; e) upon detecting of any deviation, translating the electron beam through at least one second predetermined raster pattern frame in the x-y plane that maintains the melting beam power density level substantially the same as the first predetermined raster pattern frame, but alters the substrate beam power density level in a manner so that the monitored condition returns to the predetermined condition; and f) repeating steps (a) through (e) at one or more second locations for building up layer by layer, generally along a z-axis that is orthogonal to the x-y plane, a three-dimensional layered metallic work piece.