Component production via laser‐based powder bed fusion of metals (PBF‐LB/M) is becoming reality for multiple applications. Especially for sophisticated parts, as in case of gas turbines, assurance of repeatable properties involves control of process and machine parameters. PBF‐LB/M is used to build configurable open‐porous structures—designed materials (DMs)—out of the high temperature superalloy Haynes 282 with relative densities from 35 % to 65 % . The objective is investigating positioning influence and process stability based on their relative densities in discrete scan fields and build jobs. As DMs made from Haynes 282 are not yet scientifically investigated, first the process boundaries are identified. The used PBF‐LB/M machine—EOS M 400‐4—works with four lasers in four quadrants—a quadrant benchmarking is carried out. The experiment is repeated in a second build job. Scatter is identified in quadrant and build job benchmarking. A further aspect under investigation is positioning within laser quadrants. However, keeping laser and parameter combinations constant, sample locations are assessed. A relative density dependency on the laser deflection angle—as a positional measure—is observed. The results of positioning influence and scatter are used to formulate a tolerance equation for relative densities of DMs.

The energy market for large gas turbines (LGTs) is in a transition toward improved sustainability. [1][2][3][4] Two approaches are in focus to reach this goal: Efficiency increases for LGTs powered with fossil fuels, or combusting alternative fuels such as hydrogen. [1][2][3] These developments go in hand with aggressive thermal conditions for hot gas path components in LGT's combustion and turbine section. [2,3,[5][6][7][8] Therefore, the cooling design of hot gas path components needs to be improved. [2,3,[5][6][7][8] Transpiration cooling is an efficient way to enable part operation in high-temperature environments. [5,6] To achieve the cooling effect, compressed air effuses from the cold gas side through an open-porous part to the hot gas side. [5,6] The outflowing coolant covers the hot component surface with a protective cooling film. [5,6] Geometrically defined or randomly distributed open porosity can be utilized for this cooling method. [5,6] Laser-based powder bed fusion of metals (PBF-LB/M) is an additive manufacturing technology for the production of sophisticated geometries. [2,3,8,9] Its ability to process nickel-based superalloys makes it suitable for high-temperature applications. [2,3,8,9] Process adaptations-either modifying the powder feedstock, or process and machine parameters-can be used to provoke randomly distributed porosity into PBF-LB/M components. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] For the approach of process parameter adaptions, the formation of pores is driven by the controlled introduction of defects, e.g., lack of fusion. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] In two previous studies so-called designed materials (DMs) were produced from the nickel-based superalloy Haynes 282 -UNS N07208 ). [9,22,26] Their open porosity was fabricated by lowering laser power, increasing scan speed, hatch distance, or layer thickness in comparison to a standard process parameter set. [9,22,26] Multiple studies analyzed DM's morphology regarding porosity (or RD), pore, and strut size. [9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] These investigations focus on process parameter influences and have not assessed the property's scatter. [9][10][11][12][13][14][15][16][17]20,21,[23][24][25]27] Determining the RD (or porosity) by calculating the ratio of dimensions and weight is a commonly used method for porous samples. [14,16,[20][21][22][23][24]26] For the pore and strut size, the digital assessment via microcomputed

Porous structures made from high temperature superalloys are candidates for high‐efficiency cooling applications. In this kind of product, the repeatability of flow‐relevant elements is of high interest in multiple aspects—e.g., performance, component lifetime, and costs. Configurable open‐porous materials—addressed here as designed materials (DMs)—can be produced via laser‐based powder bed fusion of metals (PBF‐LB/M) by process parameter adaptions. With the high temperature superalloy Haynes 282 DM's manufacturability was previously demonstrated on a multi‐laser EOS M 400‐4 PBF‐LB/M machine. The influence of part positioning on the respective relative density of such structures and scatter were shown and tolerance equations developed. Hence, herein, the main objective is following up on the repeatability of morphological DM properties. Therefore, DM's mean pore diameter, mean strut diameter, and surface ratio are analyzed via microcomputed tomography (μCT). A positional scatter assessment is performed. Moreover, attention is paid to the repeatability of the investigated properties over different laser quadrants and build jobs. The identified scatter is utilized in the tolerance equations formulated in this research. Furthermore, potential correlations among the properties—relative density, mean pore diameter, mean strut diameter, and surface ratio—are examined.