To characterize the structure and chemical composition along the fusion boundaries, optical microscopy and Hitachi SU6600 field-emission gun SEM (FEG-SEM) equipped with RJR-2403 dispersion spectroscopy (EDS) were used. The microhardness measurements were conducted from the substrate to the top surface according to ASTM E384 standard. The microhardness was measured by applying a load of 200 gf in 10 s using a calibrated Buehler Micromet 5101® Vickers digital microhardness tester.
2.4. Quantitative X-ray diffraction texture analysis
X-ray diffraction (XRD) analysis was carried out using a Bruker® 2D system, with Cu Kα radiation (λ = 1.54056 Å) to determine the texture of the unaffected substrate. The incomplete experimental pole figures (PFs), i.e. PFs of 111 , 200 , 220 , and 311 planes, were used to calculate the complete orientation distribution function (ODF) plots.
2.5. Electron backscatter diffraction analysis
Generally, the dislocation density in the deformed grains results in local misorientations of several degrees within grains. Thus, the analysis of kernel average neighbor misorientation (KANM) maps, which are based on the grain internal statistics and are related to the amount of residual strain, was performed to study the distribution of the residual strain across the cladding. In KANM analysis, the average misorientation of a given pixel with respect to its 3rd nearest-neighbors was calculated. In calculating the KANM, values above 5° threshold were excluded from the calculation, because Gondwana points were assumed to belong to adjacent grains .