Low carbon steel sheets with
The SEM micrographs of the polished cross-sections of the as-sprayed coatings in Fig. 2 only yielded information about the pores, cracks and nanoparticles present in the coatings, but did not allow the size and distribution of grains to be determined. Band CP690550 and orientation distribution maps of the N1 and N2 coatings were therefore obtained through EBSD analysis, which as shown in Fig. 4(b) and (e), indicate that large cracks were present at the interfaces of splattered particles. Meanwhile, small cracks were found through a combination of their SEM images in Fig. 4(a) and (d) to be located at the grain boundary interface. The orientation maps in Fig. 4(c) and (f) also show polymerase chain reaction (PCR) there are three distinct grain types in the as-sprayed coatings: columnar grains, marked with dashed rectangles and labeled as No. 1; small equiaxed grains, marked with dashed rectangles and labeled as No. 2; and a small number of large grains, which are marked with arrows. Significantly, the N2 coating clearly has a greater number of columnar grains and smaller grain size than the N1 coating; and by statistically analyzing 10,000 grains, the relative percentage of columnar grains (aspect ratio > 2) in the N1 and N2 coatings was determined to be 20.6% and 52.5%, respectively.