Provided is a method of preparing an alloy powder, comprising the steps of: melting the metal elements to produce the alloy solution; atomizing the alloy solution into small drops under oxygen-containing atmosphere; forcing the small drops to be quickly cooled under the driving of the atomizing flow to obtain the alloy powder; wherein, when the method is used to prepare CuInGa alloy powder, Cu/(In+Ga) is 0.5 to 1.1, In/(In+Ga) is 0.2 to 0.9, Ga/(In+Ga) is 0.1 to 0.8, In/(In+Ga)+Ga/(In+Ga) is 1. Also provided is an alloy powder and a method of preparing CuInGa alloy powder.

A shaped article production method includes: fabricating an intermediate article by powder bed fusion using a powder of a gamma prime precipitation strengthening Ni-based alloy; and heat-treating the intermediate article. The Ni-based alloy contains, in percent by mass, 7.0 to 17.0% Cr, 7.0 to 12.0% Co, 5.0 to 8.0% Al+Ti, 2.0 to 12.0% W, 1.5 to 4.4% Nb+Ta, 2.3% or less Mo, 0.3% or less C, 2.0% or less Hf, and 0.2% or less Zr. The fabricating the intermediate article includes applying a laser beam to a layer (3) of the powder along scan lines (4) parallel to one another. In applying the laser beam, a value obtained by dividing a pitch between the scan lines (4) by a laser spot diameter is in the range of 0.6 to 1.1.

A monolithic precursor test coupon includes a first grip portion, a second grip portion, and an intermediate portion, interconnecting the first grip portion and the second grip portion. The monolithic precursor test coupon also includes runners, directly interconnecting the first grip portion and the second grip portion and not directly connected to the intermediate portion. The first grip portion, the second grip portion, the intermediate portion, and the runners are composed of a substance that comprises metal powder and that is in a green state.

A monolithic precursor test coupon includes a first grip portion, a second grip portion, and an intermediate portion, interconnecting the first grip portion and the second grip portion. The monolithic precursor test coupon also includes runners, directly interconnecting the first grip portion and the second grip portion and not directly connected to the intermediate portion. The first grip portion, the second grip portion, the intermediate portion, and the runners are composed of a substance that comprises metal powder and that is in a green state.

An apparatus for producing three-dimensional work pieces is provided. The apparatus comprises a carrier configured to receive multiple layers of raw material, and an irradiation unit configured to generate a radiation beam and to direct the radiation beam to predetermined sites of an uppermost layer of the raw material in order to solidify the raw material at the predetermined sites. The irradiation unit comprises a radiation source configured to generate the radiation beam, a first scanning unit configured to receive the radiation beam and to scan the radiation beam over a first irradiation area of the uppermost layer of the raw material, a second scanning unit configured to receive the radiation beam and to scan the radiation beam over a second irradiation area of the uppermost layer of the raw material, and a switching unit configured to direct the radiation beam generated by the radiation source to the first scanning unit or the second scanning unit. The apparatus further comprises a control unit configured to perform control of the switching unit to switch from a first switching state, in which the radiation beam is directed to the first scanning unit and not to the second scanning unit, to a second switching state, in which the radiation beam is directed to the second scanning unit and not to the first scanning unit.

An apparatus for producing three-dimensional work pieces is provided. The apparatus comprises a carrier configured to receive multiple layers of raw material, and an irradiation unit configured to generate a radiation beam and to direct the radiation beam to predetermined sites of an uppermost layer of the raw material in order to solidify the raw material at the predetermined sites. The irradiation unit comprises a radiation source configured to generate the radiation beam, a first scanning unit configured to receive the radiation beam and to scan the radiation beam over a first irradiation area of the uppermost layer of the raw material, a second scanning unit configured to receive the radiation beam and to scan the radiation beam over a second irradiation area of the uppermost layer of the raw material, and a switching unit configured to direct the radiation beam generated by the radiation source to the first scanning unit or the second scanning unit. The apparatus further comprises a control unit configured to perform control of the switching unit to switch from a first switching state, in which the radiation beam is directed to the first scanning unit and not to the second scanning unit, to a second switching state, in which the radiation beam is directed to the second scanning unit and not to the first scanning unit.

The present invention provides a method to achieve full densification and grain size control for sintering metal materials. First, raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

A pressure detector is installed in close proximity to the nozzle of a 3D printer and detects a plugged nozzle by the sudden increase in the pressure of the extruded material. The printing process is paused until the nozzle is cleared manually or automatically. For manual cleaning a notification can be automatically sent to the user of the printer. The pressure sensor can be part of the nozzle housing and be designed to detect external forces as well, in order to serve as a bed levelling sensor.

A pressure detector is installed in close proximity to the nozzle of a 3D printer and detects a plugged nozzle by the sudden increase in the pressure of the extruded material. The printing process is paused until the nozzle is cleared manually or automatically. For manual cleaning a notification can be automatically sent to the user of the printer. The pressure sensor can be part of the nozzle housing and be designed to detect external forces as well, in order to serve as a bed levelling sensor.

A powder cleaning system can include a fluidized bed reactor configured to retain powder and fluidize the powder to remove adsorbate and/or other contaminants from the powder, at least one inlet line, and one or more gas sources configured to be in selective fluid communication with the fluidized bed reactor via the at least one inlet line to selectively provide an inlet flow having one or more gases to the fluidized bed reactor to fluidize the powder with the one or more gases within the fluidized bed reactor. The system can include at least one outlet line in fluid communication with the fluidized bed reactor and configured to allow removal of outlet flow which comprises the adsorbate and/or other contaminants from the fluidized bed reactor.