Abstract: The present invention concerns nickel alloys in powder form comprising at least 40 wt.-% Ni, about 20.0 to 25.0 wt.-% Cr, about 5.0 to 25.0 wt.-% Co and about 1.5 to 5.0 wt.-% Ti, which have a content of B in an amount of less than 40 ppmw. Corresponding alloys have the advantage of providing minimal or no micro-cracks as well as an improved ductility in creep conditions compared to similar alloys having a higher content of B, when the alloys are processed by additive manufacturing to prepare three-dimensional objects. The present invention further concerns processes and devices for the preparation of three-dimensional objects from such nickel alloy powders, processes for the preparation of corresponding nickel alloy powders, three-dimensional objects which are prepared from such nickel alloy powders and the use of such nickel alloy powders to minimize and/or suppress micro-crack formation and/or to provide improved creep ductility.

Abstract: Disclosed is a method of determining a quality indicator of an object that has been manufactured by layer-wise additive manufacturing. The method includes providing a first dataset that is assigned to a process monitoring device, detecting a relative frequency of occurrence of a process irregularity in a layer and of assigning a grade indicator value to the solidified object cross-section in a layer according to the detected relative frequency, generating a second dataset, in which a grade indicator value is assigned to the object cross-section in each of said several layers following upon one another, and determining a quality indicator by using the second dataset (or several further datasets).

Abstract: A device is disclosed for producing a three-dimensional object by layerwise construction. The device contains a flow device for generating a gas flow above an applied layer of the building material by means of a nozzle element for introducing the gas into the device. The nozzle element includes a body with a gas inlet side and a gas outlet side, and channels which penetrate the body from the gas inlet side to the gas outlet side, provided with inlet openings on the gas inlet side and gas outlet openings on the gas outlet side, and which are separated by walls. The length of the channels is selected such that a laminar flow is formed at the gas outlet side.

Abstract: Disclosed is a method of determining a quality indicator of an object that has been manufactured by layer-wise additive manufacturing . The method includes providing a first dataset that is assigned to a process monitoring device, detecting a relative frequency of occurrence of a process irregularity in a layer and of assigning a grade indicator value to the solidified object cross-section in a layer according to the detected relative frequency, generating a second dataset, in which a grade indicator value is assigned to the object cross-section in each of said several layers following upon one another, and determining a quality indicator by using the second dataset (or several further datasets).

Abstract: A device (1), for producing a three-dimensional object (2) by solidifying, layer-by-layer, building material (13) at locations in the respective layer corresponding to the cross-section of the object (2) to be produced, contains a flow device (31, 32, 34, 35) for generating a gas flow above an applied layer of the building material (13) by means of a nozzle element (40) for introducing the gas into the device. The nozzle element (40) comprises a body (41) with a gas inlet side and a gas outlet side (46), and a plurality of channels (42) which penetrate the body from the gas inlet side (44) to the gas outlet side (46), are provided with inlet openings on the gas inlet side (44) and with gas outlet openings (47) on the gas outlet side (46), and which are separated by walls (43). The length of the channels (42) is selected such that therein a laminar flow is formed at the gas outlet side (46).