The present disclosure generally relates to additive manufacturing systems and methods on a large-scale format. One aspect involves a build unit that can be moved around in three dimensions by a positioning system, building separate portions of a large object. The build unit has an energy directing device that directs, e.g., laser or e-beam irradiation onto a powder layer. In the case of laser irradiation, the build volume may have a gasflow device that provides laminar gas flow to a laminar flow zone above the layer of powder. This allows for efficient removal of the smoke, condensates, and other impurities produced by irradiating the powder (the gas plume) without excessively disturbing the powder layer. The build unit may also have a recoater that allows it to selectively deposit particular quantities of powder in specific locations over a work surface to build large, high quality, high precision objects.

A method for additive manufacturing an object is disclosed. The method includes, for a first portion of the object to be built in a first overlapping field region of a plurality of melting beams of a metal powder AM system, sequentially forming each layer of the first portion by: forming only a border section of the first portion of the object using a first melting beam of the plurality of melting beams in the first overlapping field region; and forming an internal section of the first portion of the object within the border section using at least one second, different melting beam from the first melting beam in the first overlapping field region. An entirety of an internal edge of the border section of the first portion of the object is overlapped with an entirety of an external edge of the internal section of the first portion of the object.

A method of forming a thick wall section on a specific region of a thin wall spinformed metallic tank shell includes forming a thin wall metallic tank shell blank by spinforming a metal sheet over a mandrel and removing the tank shell blank from the mandrel. The method further includes mounting the blank in an additive manufacturing system and adding metallic structural features to the tank shell according to a 3D model stored in memory in the additive manufacturing system.

A hybrid article is disclosed including a coating disposed on and circumscribing the lateral surface of a core having a core material. The coating includes about 35% to about 95% of a first metallic material having a first melting point, and about 5% to about 65% of a second metallic material having a second melting point lower than the first melting point. A method for forming the hybrid article is disclosed including disposing the core in a die, forming a gap between the lateral surface and the die, introducing a slurry having the metallic materials into the gap, and sintering the slurry, forming the coating. A method for closing an aperture of an article is disclosed including inserting the hybrid article into the aperture. Closing the aperture includes brazing the hybrid article to the article, welding the aperture with the hybrid article serving as weld filler, or a combination thereof.

A method and apparatus particularly for additively manufacturing materials that are susceptible to hot cracking. The additive manufacturing process may include a leading energy beam (16) for liquefying a raw material to form a melt pool (20), and a trailing energy beam (17) directed toward a trailing region of the melt pool. The trailing energy beam may be configured to enhance agitation and/or redistribution of liquid in the melt pool to prevent hot cracking, reduce porosity, or improve other characteristics of the solidified part. The method and apparatus also may improve processing parameters, such as adjusting vacuum level to prevent volatilization of alloying agents, or providing a chill plate to control interpass temperature. The process may be used to form new articles, and also may be used to enhance tailorability and flexibility in design or repair of pre-existing articles, among other considerations.

Provided are a systems and methods for continuously providing a metal wire to a welding torch for manufacturing objects by solid freeform fabrication to provide continuous deposition of metal to the freeform object, especially objects made with titanium or titanium alloy wire.

Aspects of the present disclosure relate generally to preparing models of three-dimensional structures. In particular, a model of a three-dimensional structure constructed of porous geometries is prepared. A component file including a porous CAD volume having a boundary is prepared. A space including the porous CAD volume is populated with unit cells. The unit cells are populated with porous geometries having a plurality of struts having nodes on each end. The space is populated with at least one elongated fixation element extending beyond the boundary to produce an interlocking feature enabling assembly or engagement with a mating structure.

A method of generating a spatial map of sensor data collected during additive manufacturing, in which a plurality of layers of powder are selectively melted with an energy beam to form an object. The method includes receiving sensor data collected during additive manufacturing of an object, the sensor data including sensor values, the sensor values captured for different coordinate locations of the energy beam during the additive manufacturing of the object, and generating cell values for a corresponding cell-based spatial mapping of the sensor data. Each of the cell values is determined from a respective plurality of the sensor values extending over an area/volume comparable to an extent of the melt pool or the energy beam spot.

This disclosure describes various methods and apparatus for characterizing an additive manufacturing process. A method for characterizing the additive manufacturing process can include generating scans of an energy source across a build plane; measuring an amount of energy radiated from the build plane during each of the scans using an optical sensor; determining an area of the build plane traversed during the scans; determining a thermal energy density for the area of the build plane traversed by the scans based upon the amount of energy radiated and the area of the build plane traversed by the scans; mapping the thermal energy density to one or more location of the build plane; determining that the thermal energy density is characterized by a density outside a range of density values; and thereafter, adjusting subsequent scans of the energy source across or proximate the one or more locations of the build plane.

A process includes forming a printed article having an external surface and at least one microfeature with an internal surface by additive manufacture, coating the external surface and the internal surface of the printed article with a metallic microlayer to form a coated article, and densifying the coated article to form a component. After formation, the printed article has a porosity such that the printed article is not at full density. A densified component includes a printed article having an external surface and at least one microfeature with an internal surface and a metallic microlayer coating the external surface and the internal surface of the printed article. The printed article is formed by additive manufacture.