Abstract: A laser powder bed fusion additive manufacturing method including performing laser melting of layers of a powder bed of steel powder in a protective atmosphere including nitrogen, wherein a temperature of the powder bed is below 220° C. A composition of the steel powder may include, by weight: 3% to 7% Cr, 2-5% Mo, 0.2% to 0.7% V, max 0.7% Si, max 1% Mn, max 1.5% C, and a balance of Fe.

Abstract: A method produces a workpiece including molybdenum, or tungsten, or chromium, or molybdenum alloy, or tungsten alloy, or chromium alloy by selective consolidation of successive layers of powder by an energy beam. The method includes performing the selective consolidation of the powder layer in a protective atmosphere including nitrogen.

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 method wherein an object is formed by selectively solidifying layers of powder with at least one energy beam. The method includes forming the object from a nickel-based superalloy, wherein exposure parameters and an exposure pattern for the at least one energy beam result in the object having a directionally solidified microstructure with columnar grains aligned with a build direction, perpendicular to the layers. A composition of the nickel-based alloy by weight % may include: 9.3-9.7W, 9.0-9.5Co, 7.5-8.5Cr, 5.4-5.7Al, 3.1-3.3Ta, 1.4-1.6Hf, 0.6-0.9Ti, Mo 0.4-0.6, 007-0.015Zr, 0.01-0.02B with a carbon concentration of around 0.07-0.09 wt % and a balance of Ni.

Abstract: A powder bed fusion additive manufacturing method includes forming layers of powder of a powder bed and exposing the layers to one or more energy beams to melt the powder to form an object. The exposure of each layer to the or each energy beam forms melt pools in a conduction or transition mode with an exposure distance between adjacent exposures within the layer being 40% to 60% of a width of the melt pools generated by the exposures and an offset of exposures between successively melted layers in a direction in which the exposure distance is measured being 40% to 60% of the exposure distance.

Abstract: A device for measuring powder bed density (PBD) (powder density for a layer) in additive manufacturing (AM) during operation. The device comprises means for determining a mass of the powder and means for determining a volume of the powder during spreading, thereby allowing determination of the powder bed density (powder density for the layer). The means for determining a volume of the powder comprises a laser assembly adapted to move a laser across a powder layer surface in both left and right directions for scanning. The device further allows for the determination of the layer surface profile as well as static and dynamic powder characteristics of the processes involved in the AM operation.

Abstract: The additively-manufactured article generally has a plurality of slices fused atop one another, at least one of the plurality of slices having a first portion including a first microstructure and a second portion including a second microstructure.