PSI - Issue 68

Shahriar Afkhami et al. / Procedia Structural Integrity 68 (2025) 929–935 S. Afkhami et al. / Structural Integrity Procedia 00 (2025) 000–000

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significantly higher number of detected defects (≈ 430 in total) in the investigated area compared to the same area in 316L (≈ 38 in total) and Ti64 (≈ 21 in total). However, 90% of these defects in Al5X1 are smaller than 25 μm 2 , and the largest defect detected was smaller than 500 μm 2 ; the largest defects detected in Ti64 and 316L were 90 μm 2 and 180 μm 2 , respectively. Accordingly, 100% of the defects were smaller than 500 μm 2 in all the investigated cases. In addition, almost all the detected defects had a circularity index higher than 0.5, and 75% of them in all three used metals for additive manufacturing had ≈ 1.0 circularity Indexes and were deemed fully round and fine-sized porosities. Consequently, such round and small isolated defects were considered relatively harmless and not prone to instigating catastrophic failures in the components [11,12].

Fig. 2. Optical microscopy (left), defect distribution (middle), and SEM image of the (etched) samples: (a) 316L, (b) Al5X1, and (c) Ti64.

Fig. 3. Frequency and distribution of defects based on their size (left) and circularity (right) in the manufactured components.