In this investigation, high carbon steel wire is deposited on aluminum cylinder bores with different surface profiles by plasma transferred wire arc (PTWA) spraying. The first part of the study deals with feedstock materials, process parameters, droplet formation, and splat morphology. The second part deals with bead profiles, build rates, and the influence of substrate composition, temperature, and surface profile on coating characteristics including microstructure, morphology, composition, and bond strength.

This study evaluates the effect of laser texturing on the bonding strength of cylinder bore coatings deposited by plasma transferred wire arc (PTWA) spraying. Experiments were carried out on an AlSi 9 Cu 3 engine block sectioned along a plane through the length of the bores. Cylinder surfaces were laser textured on one side and degreased and grit blasted on the other. Laser power, beam angle, and pulse count were varied to determine their effect on hole morphology and coating adhesion. After surface treatment, the engine block sections were rejoined and the cylinder bores were PTWA sprayed with high carbon steel. Coating samples were examined by SEM and cross-sectional analysis and adhesion tests were conducted. The bonding strength of the coatings on the laser textured portion of the cylinder bore was significantly higher than that of the coatings on grit-blasted surfaces and is shown to vary with laser power, beam angle, and total pulses or impacts per hole.