Abstract: A selective solidification apparatus includes a build chamber, a build platform lowerable in the build chamber, a wiper for spreading powder material across the build platform to form successive powder layers of a powder bed, an energy beam unit for generating an energy beam for consolidating the powder material, a scanner for directing and focussing the energy beam onto each powder layer and a processor for controlling the scanner. The processor is arranged to control the scanner to scan the energy beam across the powder bed to consolidate powder material either side of the wiper when the wiper is moving across the powder bed and to scan the energy beam across at least one of the powder layers during two or more strokes of the wiper across the powder bed.

Abstract: A method of determining instructions to be executed by a powder bed fusion apparatus, in which an object is built in a layer-by-layer manner by selectively irradiating regions of successively formed powder layers with an energy beam. The method includes determining an exposure parameter for each location within a layer to be irradiated with the energy beam from a primary exposure parameter, the exposure parameters varying with location. An amount each exposure parameter varies from the primary exposure parameter is determined, at least in part, from a geometric quantity of the object derived from the location of the irradiation.

Abstract: An additive manufacturing apparatus including a scanner for directing a laser beam on to layers of flowable material to selectively solidify the material to form an object in a layer-by-layer manner. The scanner includes an optical component operable under the control of a first actuator to reflect the laser beam over a first range of angles in a first dimension and the or a further optical component operable under the control of a second actuator to reflect the laser beam over a second range of angles in the first dimension, wherein the second actuator provides a faster dynamic response but a smaller range of movement of the laser beam than the first actuator.

Abstract: A method for determining an attribute of an additive manufacturing apparatus including a plurality of scanners, each scanner including beam steering optics for directing a corresponding radiation beam to a working plane in which material consolidated in layers. The method may include controlling the beam steering optics of a pair of the scanners wherein a first scanner of the pair directs a radiation beam to form a feature in the working plane. The feature is within a field of view of a detector of the second scanner of the pair, the detecting radiation from the working plane is collected by the beam steering optics of the second scanner. Further including recording at least one detector value with the detector of the second scanner for the field of view and determining an attribute of the additive manufacturing apparatus from a comparison of the detector value with an expected detector value.

Abstract: A method of monitoring an additive manufacturing apparatus. The method includes receiving one or more sensor signals from the additive manufacturing apparatus during a build of a workpiece, comparing the one or more sensor signals to a corresponding acceptable process variation of a plurality of acceptable process variations and generating a log based upon the comparisons. Each acceptable process variation of the plurality of acceptable process variations is associated with at least one state of progression of the build of the workpiece and the corresponding acceptable process variation is the acceptable process variation associated with the state of progression of the build when the one or more sensor signals are generated.

Abstract: An additive manufacturing apparatus including a scanner for directing a laser beam on to layers of flowable material to selectively solidify the material to form an object in a layer-by-layer manner. The scanner includes an optical component operable under the control of a first actuator to reflect the laser beam over a first range of angles in a first dimension and the or a further optical component operable under the control of a second actuator to reflect the laser beam over a second range of angles in the first dimension, wherein the second actuator provides a faster dynamic response but a smaller range of movement of the laser beam than the first actuator.

Abstract: A selective laser solidification apparatus including; a powder bed onto which powder layers can be deposited, at least one laser module for generating a plurality of laser beams for solidifying the powder material deposited onto the powder bed, a laser scanner for individually steering each laser beam to solidify separate areas in each powder layer, and a processing unit. A scanning zone for each laser beam is defined by the locations on the powder bed to which the laser beam can be steered by the laser scanner. The laser scanner is arranged such that each scanning zone is less than the total area of powder bed and at least two of the scanning zones overlap. The processing unit is arranged for selecting, for at least one powder layers, which laser beam to use to scan an area of the powder layer located within a region wherein the seaming zones overlap.

Abstract: An additive manufacturing apparatus including a scanner for directing a laser beam on to layers of flowable material to selectively solidify the material to form an object in a layer-by-layer manner. The scanner includes an optical component operable under the control of a first actuator to reflect the laser beam over a first range of angles in a first dimension and the or a further optical component operable under the control of a second actuator to reflect the laser beam over a second range of angles in the first dimension, wherein the second actuator provides a faster dynamic response but a smaller range of movement of the laser beam than the first actuator.

Abstract: A method controls an additive manufacturing apparatus, in which an object is built by consolidating material in a layer-by-layer manner. The method includes receiving commands to be executed by the additive manufacturing apparatus to cause the additive manufacturing apparatus to carry out a build of an object, wherein each command includes an identifier identifying a time during the build at which the command is to be executed, and executing each command on the additive manufacturing apparatus in accordance with the time identified by the associated identifier. Further, an apparatus and a data carrier carry out the method.

Abstract: A module for an additive manufacturing apparatus including more than one optical train, each optical train providing a route for a laser beam to pass through the module and including steering optics for steering the laser beam towards the material to be consolidated as part of a layer-by-layer additive manufacturing process. The module is configured to deliver laser beams from the more than one optical trains through a single window in a build chamber of the additive manufacturing apparatus.

Abstract: A method of aligning an on-axis melt pool sensor in an additive manufacturing apparatus. The method includes scanning a first laser beam along a first scan path across a working surface using a first optical train to generate a melt pool along the first scan path and scanning a field of view of an on-axis sensor along a second scan path across the working surface using a second optical train for steering a second laser beam. The first and second scan paths intersect. An adjustment to be made to an alignment of the field of view of the on-axis sensor with an optical axis of the second optical train is determined from a variation in the signal generated by the on-axis sensor as the field of view is scanned along the second scan path.

Abstract: A method controls an additive manufacturing apparatus, in which an object is built by consolidating material in a layer-by-layer manner. The method includes receiving commands to be executed by the additive manufacturing apparatus to cause the additive manufacturing apparatus to carry out a build of an object, wherein each command includes an identifier identifying a time during the build at which the command is to be executed, and executing each command on the additive manufacturing apparatus in accordance with the time identified by the associated identifier. Further, an apparatus and a data carrier carry out the method.

Abstract: An additive manufacturing apparatus including a build chamber, build platform lowerable in the chamber so layers of flowable material can successively form across the platform, laser for generating a laser beam, scanning unit for directing the laser beam onto each layer to selectively solidify the material and a processor for controlling the scanning unit. The processor controls the scanning unit directs the laser beam to solidify a selected area of material by advancing the laser beam many times along a scan path. On each pass, the laser beam solidifies spaced apart sections of the scan path, each subsequent pass solidifying sections that are located between sections solidified on a previous pass. The processor controls the scanning unit to direct the laser beam to solidify selected area of material by solidifying sub-millimetre sized sections of non-continuously area and in an order such that consecutively solidified sections are spaced apart.

Abstract: A method of monitoring an additive manufacturing process, in which an object is built in a layer-by-layer manner by directing a laser beam using at least one movable guiding element of a scanner to solidify selected regions of a material bed. The method includes recording position values generated from a transducer measuring positions of the at least one movable guiding element, recording sensor values generated from a sensor for detecting radiation emitted from the material bed and transmitted to the sensor by the movable guiding element of the scanner, and associating each sensor value with a corresponding one of the position values.

Abstract: A method of filtering gas in a powder bed fusion apparatus, wherein an object is built layer-by-layer by selective solidification of a powder bed, and a powder bed fusion apparatus for executing the method. The apparatus includes a build chamber housing the powder bed, a gas circuit for recirculating the gas, including passing the gas over the powder bed within the build chamber, multiple filter assemblies in the gas circuit for filtering process emissions from the recirculated gas and a valve system regulating gas flow to each filter assembly. The method may include controlling the valve system to divide the gas flow between the filter assemblies. The method includes controlling the valve system such that a first one of the filter assemblies is connected with at least one second one of the filter assemblies such that the gas passes through the filter elements of both filter assemblies.

Abstract: A selective solidification apparatus includes a build chamber, a build platform lowerable in the build chamber, a wiper for spreading powder material across the build platform to form successive powder layers of a powder bed, an energy beam unit for generating an energy beam for consolidating the powder material, a scanner for directing and focussing the energy beam onto each powder layer and a processor for controlling the scanner. The processor is arranged to control the scanner to scan the energy beam across the powder bed to consolidate powder material either side of the wiper when the wiper is moving across the powder bed and to scan the energy beam across at least one of the powder layers during two or more strokes of the wiper across the powder bed.

Abstract: This invention concerns a method of monitoring an additive manufacturing apparatus. The method comprises receiving one or more sensor signals from the additive manufacturing apparatus during a build of a workpiece, comparing the one or more sensor signals to a corresponding acceptable process variation of a plurality of acceptable process variations and generating a log based upon the comparisons. Each acceptable process variation of the plurality of acceptable process variations is associated with at least one state of progression of the build of the workpiece and the corresponding acceptable process variation is the acceptable process variation associated with the state of progression of the build when the one or more sensor signals are generated.

Abstract: A selective solidification apparatus includes a build chamber, a build platform lowerable in the build chamber, a wiper for spreading powder material across the build platform to form successive powder layers of a powder bed, an energy beam unit for generating an energy beam for consolidating the powder material, a scanner for directing and focusing the energy beam onto each powder layer and a processor for controlling the scanner. The processor is arranged to control the scanner to scan the energy beam across the powder bed to consolidate powder material either side of the wiper when the wiper is moving across the powder bed and to scan the energy beam across at least one of the powder layers during two or more strokes of the wiper across the powder bed.

Abstract: A method of monitoring an additive manufacturing apparatus. The method includes receiving one or more sensor signals from the additive manufacturing apparatus during a build of a workpiece, comparing the one or more sensor signals to a corresponding acceptable process variation of a plurality of acceptable process variations and generating a log based upon the comparisons. Each acceptable process variation of the plurality of acceptable process variations is associated with at least one state of progression of the build of the workpiece and the corresponding acceptable process variation is the acceptable process variation associated with the state of progression of the build when the one or more sensor signals are generated.

Abstract: An additive manufacturing apparatus including a build chamber in which an object is built and a flow device. The flow device comprises a body having a Coand{hacek over (a)} surface and a passageway connectable to a pressurised gas source. The passageway has an opening located adjacent to the Coand{hacek over (a)} surface to, in use, direct a jet of gas over the Coand{hacek over (a)} surface. A space adjacent the Coand{hacek over (a)} surface is in fluid communication with the build chamber such that gas drawn into and/or propelled from the space causes gas flow through the build chamber.