An apparatus (1) for manufacturing a three-dimensional object from particulate material, the apparatus comprising: a work space (100) bounded by a first side wall (100A) on a first side of the work space, and a second side wall (100B) on a second side of the work space, the first side wall opposing the second side wall; a build bed (170) having a build bed surface (160), the build bed surface being comprised in the floor of the work space and having a first edge (160′) on the first side of the work space, towards the first side wall, and a second edge (160″) on the second side of the work space, towards the second side wall; a first gas inlet (101A) at or near the first side wall; a second gas inlet (101B) at or near the second side wall; a first gas outlet (102A) above the floor (100C) of the work space, the position of the first gas outlet being coincident with the first edge of the build bed surface, or between the first edge of the build bed surface and the first gas inlet; and a second gas outlet (102B) above the floor of the work space, the position of the second gas outlet being coincident with the second edge of the build bed surface, or between the second edge of the build bed surface and the second gas inlet; wherein the first gas outlet is positioned higher in the work space than the first gas inlet, and the second gas outlet is positioned higher in the work space than the second gas inlet; and wherein one or more flow devices (210, 211, 212) are operable to create first and second gas flows between the first gas inlet and the first gas outlet, and between the second gas inlet and the second gas outlet, respectively, such as to create respective first and second gas curtains on the first and second sides of the work space in use.

The invention relates to a material feeding device. The material feeding device according to the invention to be used in a material processing device has a material feeding channel with an output end facing a processing site during operation of the material feeding device, and is characterized in that the material feeding device has at least one microchannel.

The invention relates to a material feeding device. The material feeding device according to the invention to be used in a material processing device has a material feeding channel with an output end facing a processing site during operation of the material feeding device, and is characterized in that the material feeding device has at least one microchannel.

Reactive ammonium carboxyl ate salts, polyamide amic acid oligomers, and polyamideimide oligomers are made from at least one aromatic diamine, at least one aromatic di-, tri-, or tetra-functional carboxylic acid or functional equivalent thereof, and at least one crosslinkable monomer or crosslinkable end-capper. The crosslinkable monomer or crosslinkable end-capper is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after formation of the reactive polyamideimide oligomer. The reactive polyamide amic acid and polyamideimide oligomers have a number average molecular weight (M.sub.n) of about 1,000 to about 10,000 g/mol, calculated using the Carothers equation. The reactive ammonium carboxyl ate salts, polyamide amic acid oligomers, and polyamideimide oligomers are useful in a wide variety of functional materials, manufacturing methods, and articles.

Embodiments relate to in-situ process monitoring of a part being made via additive manufacturing. The process can involve capturing computed tomography (CT) scans of a post-built part. A neural network (NN) can be used during the build of a new part to process multi-modal sensor data. Spatial and temporal registration techniques can be used to align the data to x,y,z coordinates on the build plate. During the build of the part, the multi-modal sensor data can be superimposed on the build plate. Machine learning can be used to train the NN to correlate the sensor data to a defect label or a non-defect label by looking to certain patterns in the sensor data at the x,y,z location to identify a defect in the CT scan at x,y,z. The NN can then be used to predict where defects are or will occur during an actual build of a part.

The present disclosure relates to composites, systems, and methods for making the same. In particular, the present disclosure relates to composites that are useful for thermal protection applications, and systems and methods for making the same.

A method for forming a three-dimensional article through successive fusion of parts of a powder bed comprising: providing a model of the three dimensional article, applying a first powder layer on a work table, directing an energy beam over the work table causing the first powder layer to fuse in selected locations according to the model to form a first cross section of the three-dimensional article, applying a second powder layer on the work table, directing the energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a second cross section of the three-dimensional article, wherein the second layer is bonded to the first layer, detecting a local thickness in at least two positions in at least the second powder layer, varying an energy beam parameter depending on the detected local thickness of the second powder layer.

A method for forming a three-dimensional article through successive fusion of parts of a powder bed comprising: providing a model of the three dimensional article, applying a first powder layer on a work table, directing an energy beam over the work table causing the first powder layer to fuse in selected locations according to the model to form a first cross section of the three-dimensional article, applying a second powder layer on the work table, directing the energy beam over the work table causing the second powder layer to fuse in selected locations according to the model to form a second cross section of the three-dimensional article, wherein the second layer is bonded to the first layer, detecting a local thickness in at least two positions in at least the second powder layer, varying an energy beam parameter depending on the detected local thickness of the second powder layer.

Selective laser solidification apparatus is described that includes a powder bed onto which a powder layer can be deposited and a gas flow unit for passing a flow of gas over the powder bed along a predefined gas flow direction. A laser scanning unit is provided for scanning a laser beam over the powder layer to selectively solidify at least part of the powder layer to form a required pattern. The required pattern is formed from a plurality of stripes or stripe segments that are formed by advancing the laser beam along the stripe or stripe segment in a stripe formation direction. The stripe formation direction is arranged so that it always at least partially opposes the predefined gas flow direction. A corresponding method is also described.

Selective laser solidification apparatus is described that includes a powder bed onto which a powder layer can be deposited and a gas flow unit for passing a flow of gas over the powder bed along a predefined gas flow direction. A laser scanning unit is provided for scanning a laser beam over the powder layer to selectively solidify at least part of the powder layer to form a required pattern. The required pattern is formed from a plurality of stripes or stripe segments that are formed by advancing the laser beam along the stripe or stripe segment in a stripe formation direction. The stripe formation direction is arranged so that it always at least partially opposes the predefined gas flow direction. A corresponding method is also described.