PSI - Issue 74

Kipkurui Ronoh et al. / Procedia Structural Integrity 74 (2025) 77–84 Kipkurui Ronoh / Stru ctural Integrity Procedia 00 (202 5 ) 000 – 000

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Fig. 3: Topographical images of ablated surfaces of MONEL® alloy 400 as a function of hatching distance of a) 5, b) 20, c) 50 and d) 100 µm.

Table 3: Effect of laser fluence on surface roughness on the surfaces of the alloys Laser Fluence (J/cm²) Surface Roughness, Sa, (μm) 699 XA Kanthal® AF MONEL® Alloy 400 Polished 0.03 0.02 0.02 1 0.07 0.05 0.07 4 0.19 0.14 0.23 8 0.12 0.30 0.19 10 0.19 0.42 0.25

3.3. Surface composition of the laser - ablated samples Fig. 4a) shows survey spectra for 699 XA ablated various laser fluences and the same scanning velocity, hatching distance and scanning pass of 100 mm/s, 5 µm and 1 scanning pass, respectively. All the 699 XA samples show similar spectra, as depicted in Fig. 4. Similar observations were made on Kanthal® AF and MONEL® alloy 400.

Fig. 4: a) XPS survey spectra for the 699 XA alloy before and after laser irradiation using laser fluence (LF) of 1, 4, 8 and 10 J/cm 2 ; b) High resolution spectrum of C 1s peak of the laser-ablated alloy 699 XA under 1 J/cm 2 .

The main elements found on the surfaces of the 699 XA were Ni, Cr, C, and O. For Monel® alloy 400, the main elements detected on the surfaces were Ni, Cu, C, and O while in Kanthal® AF, the main elements determined on the