Method and apparatus for creating a free-form three-dimensional metal part using high-temperature direct laser melting

Abstract

A computer-controlled apparatus and method for producing metallic parts by laser melting selected regions of a layer(s) of metal powder at a target area are disclosed. The system includes devices for preheating and maintaining a relatively high temperature, e.g. 400.degree. C., of the metal powder so as to join the metal powder together with relatively low laser power, e.g. a 200W CO.sub.2 laser. A major powder depositing mechanism with a scraper and a depositing system for a secondary powder are included in the apparatus that allows the powders to be delivered to the target area for selective melting. The metal powder is preheated at either a dispensing cylinder or the target area through thermal conduction and/or is also heated by a heating plate positioned above the platform through radiation. The corresponding machine structures, such as a motion system and a working chamber, are designed to be able to withstand and operated under the high temperature environment.