PSI - Issue 53

Francisco Matos et al. / Procedia Structural Integrity 53 (2024) 270–277 Francisco Matos et al. / Structural Integrity Procedia 00 (2023) 000–000

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Material samples in the format of tensile specimens were produced in the same batch of the tooling prototype, allowing for further mechanical properties assessment. Tensile tests were performed on a 300 kN Instron 5900R testing machine. The experimental conditions are shown in Table 2. DIC (Digital Image Correlation) was employed in the tensile testing, o ff ering precise strain measurement and deformation analysis. An identical setup configuration to Cruz et al. (2020), ensured consistency in experimental conditions and data comparability.

Table 2: Experimental conditions for 316L AM samples.

Number of samples Gauge length ( L 0 ) Crosshead speed

2

20mm

2.5mm / min

Frequency of data acquisition 10 Hz

In Figure 2 engineering stress–strain curves for the 316L specimens are shown. The tensile testing revealed repeata bility and properties well-aligned with successfully processed additively manufactured materials and testing setups in literature Lec¸a et al. (2020). Table 3 summarizes the results of the tensile tests.

Table 3: Test resuls for 316L AM samples.

Sample Yield stress (MPa) Ultimate tensile strength (MPa) Elongation (%) 1 466.14 629.48 45.65 2 471.58 626.80 44.97

Fig. 2: Engineering stress-strain curves of AM 316L.

The transversal microstructure of AISI 316L manufactured using LPBF after polishing and etching with saturated Picral is presented in Figure 3. This microstructure has a fish-scale morphology, common in selective laser melted parts, without major defects such as porosities or inclusions Hou et al. (2020). Overlapping melt pools ensure that powder particles are totally fused together resulting in adequate layer bonding. Additionally, it is possible to see solidified melt pools encompassing elongated grains constituted by columnar and cellular dendrites a ff ected by the