An apparatus for producing a three-dimensional work piece is provided. The apparatus comprises an irradiation unit comprising at least one scanning unit configured to scan a radiation beam over an uppermost layer of raw material powder to predetermined sites of the uppermost layer of the raw material powder in order to solidify the raw material powder at the predetermined sites. An axis corresponding to the radiation beam when it impinges on the uppermost layer of raw material powder at an angle of 90° is defined as a central axis for the scanning unit. The apparatus further comprises a control unit configured to receive work piece data indicative of at least one layer of the three-dimensional work piece to be produced, and assign at least a part of a contour of the layer of the three-dimensional work piece to the at least one scanning unit. According to a first aspect, the control unit is configured to generate control data for controlling the irradiation unit, the control data defining a scan strategy of the radiation beam such that for more than 50% of a predefined length, the radiation beam moves away from the central axis, the predefined length being defined as a length the radiation beam moves along the contour assigned to the at least one scanning unit, excluding sections concentric with regard to the central axis. Further, corresponding methods and computer program products are provided.

An electron beam melting machine and a method of operation are provided which maintains constant energy absorption within a build layer by adjusting an incident energy level to compensate for energy not absorbed by the additive powder. This unabsorbed energy is detected in the form of electron emissions, which include secondary electrons, backscattered electrons, and/or electrons which are transmitted through the build platform.

The present disclosure discloses a nano-lanthanum oxide reinforced tungsten-based composite material and a preparation method thereof. A pure tungsten powder and a nano-lanthanum oxide powder are mixed to obtain a mixed powder, and in the mixed powder, the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; and then, 3D printing forming is conducted on the mixed powder to obtain a bulk material of the nano-lanthanum oxide reinforced tungsten-based composite material. The nano-lanthanum oxide reinforced tungsten-based composite material of the present disclosure has excellent mechanical properties.

The present disclosure discloses a nano-lanthanum oxide reinforced tungsten-based composite material and a preparation method thereof. A pure tungsten powder and a nano-lanthanum oxide powder are mixed to obtain a mixed powder, and in the mixed powder, the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; and then, 3D printing forming is conducted on the mixed powder to obtain a bulk material of the nano-lanthanum oxide reinforced tungsten-based composite material. The nano-lanthanum oxide reinforced tungsten-based composite material of the present disclosure has excellent mechanical properties.

A lamination molding apparatus includes a molding room, a chamber, a chamber window, a molding table, a molding table driving device, surrounding walls, an irradiation device, a measuring unit, and a controller. The measuring unit includes a first measuring device acquiring a measured value of a light intensity, and a second measuring device acquiring a value of a beam diameter, and measures laser beams outputted based on set values of light intensity during molding. The controller determines an abnormality has occurred when a slope of a linear function obtained from a relationship between the measured value of the light intensity and the value of the beam diameter at a predetermined height is out of a predetermined range, or when a slope of a linear function obtained from a relationship between the measured value of the light intensity and a value of a focal position is out of a predetermined range.

A lamination molding apparatus includes a molding room, a chamber, a chamber window, a molding table, a molding table driving device, surrounding walls, an irradiation device, a measuring unit, and a controller. The measuring unit includes a first measuring device acquiring a measured value of a light intensity, and a second measuring device acquiring a value of a beam diameter, and measures laser beams outputted based on set values of light intensity during molding. The controller determines an abnormality has occurred when a slope of a linear function obtained from a relationship between the measured value of the light intensity and the value of the beam diameter at a predetermined height is out of a predetermined range, or when a slope of a linear function obtained from a relationship between the measured value of the light intensity and a value of a focal position is out of a predetermined range.

A pre-alloyed powder having a composition consisting of, in weight % (wt. %): C, 0.02-0.04; Si, 0.1-0.4; Mn, 0.1-0.5; Cr, 11-13; Ni, 7-10; Cr+Ni, 19-23; Mo, 1-25; Al, 1.4-2.0; N, 0.01-0.75. Optionally, the pre-alloyed powder contains: Cu, 0.05-2.5; B, 0.002-2.0; S, 0.01-0.25; Nb, 0.01 max; Ti, 2 max; Zr, 2, max; Ta, 2 max; Hf, 2 max; Y, 2 max; Ca, 0.0003-0.009; Mg, 0.01 max; O, 0.003-0.80; and REM, 0.2 max. Fe and impurities comprise the balance.

An additive manufacturing system including a housing configured to contain a powder bed of material, and an array of laser emitters having a field of view. The array is configured to melt at least a portion of the powder bed within the field of view as the array translates relative to the powder bed. The system further includes a spatter collection device including a diffuser configured to discharge a stream of gas across the powder bed, and a collector configured to receive the stream of gas and contaminants entrained in the stream of gas. The collector is spaced from the diffuser such that a collection zone is defined therebetween, and the spatter collection device is configured to translate relative to the powder bed such that the collection zone overlaps with the field of view of the array.

An irradiation device for an additively manufacturing apparatus may include a working beam generation device configured to provide a working beam, a modulation beam generation device configured to provide a modulation beam, and a solid-state optical modulator that includes a crystalline material that exhibits a change in refractive index in response to photoexcitation of free electrons within the crystalline material. The irradiation device may include a power source coupled to the solid-state optical modulator and configured to introduce free electrons into the crystalline material. The modulation beam may cause photoexcitation of the free electrons within the crystalline material. The photoexcitation of the free electrons within the crystalline material may cause the crystalline material to exhibit a change in refractive index. The working beam, when incident upon the crystalline material, may exhibit a change in one or more parameters, such as a phase shift, attributable at least in part to the change in refractive index exhibited by the crystalline material.

Methods, systems, and apparatus, for hybrid additive manufacturing of parts. In one aspect, a method includes providing a workpiece and manufacturing multiple additive layers on a surface of the workpiece. Manufacturing each of the multiple additive layers includes forming one or more formed layers on a surface of the workpiece by depositing a quantity of powder material on a growth surface, the growth surface inclusive of at least one of a first surface of the workpiece and a second surface of a previously formed layer, and applying a first amount of energy to the quantity of powder material to fuse the particles of the powder material into a formed layer fused to the growth surface, where the formed layer includes a formed surface, and further applying a secondary process to a particular area of the formed surface of the one or more formed layers on the workpiece.