PSI - Issue 68

Matias Jaskari et al. / Procedia Structural Integrity 68 (2025) 480–485 M. Jaskari et al. / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 1. (a) Schematic of the printed axial fatigue sample and (b) temperature history of the annealing treatment.

Fig. 2. Surface roughness profiles of (a) as built and (b) electropolished sample.

3. Results and Discussion 3.1. Microstructure

After heat treatment, microstructure of the material was examined using EBSD, and the resulted images are presented in Fig. 3. Some epitaxial growth is present in cross-sectional sample in respect to the build (Z) direction (Fig 3a). In XY-direction (Fig 3b.) the crystallographic microstructure is more homogenous, although some smaller grains are present between the laser hatching tracks. Measured grains sizes were 162 and 74 µm in building and XY direction, respectively. EBSD measurement show the phase structure to be fully face-centered cubic (FCC) structure, but most likely some amount of brittle Laves phase is present, as is common for heat-treated In718 (Volpato et al., 2022). Some crystallographic texture is seen in respect of building direction, and the grains have slightly preferred orientation in <110>-direction, as is shown in Fig 3c.