Properties and performance of the coating fabricated by wire arc spray process strongly depend on various factors including spray parameters and characteristics of both in-flight particle and splat. In this study, relationship between in-flight particle, splat formation and microstructure of the CrMoBW-Fe based nanocomposite coating fabricated by wire arc spray process were investigated. The Focus ion beam (FIB) milling was used to prepare a transversal cross-section of the in-flight particle and splat to be characterized by scanning electron microscopy (SEM) along with an energy dispersive x-ray spectroscopy (SEM-EDS). In addition, phase compositions were also analyzed by using x-ray diffractometer (XRD). The results revealed that size of the in-flight particles and splat morphology greatly influenced microstructure and properties of the coatings. In-flight particles were revealed a spherical-shape with a broad size distribution ranging from 0.8 to 115 µm at the average of 26 µm particle diameter. In-flight particles were well flattened on impact giving flower-shape splat with the average diameter of 100 µm. Flattening degree was found to be 3.8. Arc sprayed CrMoBW-Fe base nanocomposite coating showed very thin splat with fine lamella structure which implied that particles were fully molten upon impact onto substrate.

Microstructures and properties of electrical arc sprayed cored-wired coatings were investigated and compared in this work. Three types of cored-wired studied were WC-Ni, WC-Fe and nano WC-Fe The as-received cored-wire were characterized prior to be sprayed. In-flight particles were collected during spraying in order to reveal particle morphology and size distribution forming splats. Size distribution analysis of the filler particles showed that nanostructured WC-Fe had a comparable mean filler particle size with that of the WC-Fe and were larger than that of the WC-Ni. The difference in filler particle size of starting cored-wire was well correlated with the in-flight particle size produced. Nano WC-Fe cored wire coating had the lowest porosity and roughness compared to others with a comparable hardness to WC-Ni cored wire coating with rather different coating microstructures.