| 摘要 |
A method for layer-by-layer manufacturing of a three-dimensional metallic work piece, comprising the steps of: delivering a metallic feed material in a substantially solid slate into a feed region: emitting an electron beam having one or more predetermined electrical currents; translating the electron beam through a first predetermined raster pattern frame in an x-y plane that includes: 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 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 (e.g., lower than) the melting beam power density level; 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; 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 repeating the above steps 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. The teachings herein also contemplate an apparatus that includes an electronic control device that performs any of the methods herein, as well as articles made according to such methods. |
