Copper coatings were deposited on ferrous substrates by utilizing high-velocity oxy-fuel spraying (HVOF). Three different coating process parameters have been used in order to optimise the required electrical characteristics. Microstructure and phase formation in the coatings were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), and oxygen analyzer (ELTRA). Electrical resistivity of coatings was measured in-plane and through-thickness using the four-contact method. Results shown that dense coatings with high purity and low level of porosity are required to achieve high electrical conductivity. The coatings exhibited an anisotropic electrical resistivity due to the nature of the thermal spray coating microstructure. Microstructural evaluation shown that individual splats morphology and splats interfaces play important roles in the electrical conductivity.

In this research mechanically alloyed Ni-Al powders were used for production of plasma sprayed coatings and effect of spray distance on the phases, microstructure and hardness of the coatings are examined. Three types of Ni-Al powder were made by METCO, LobaChemi and mechanical alloying, were used for comparing coating properties. Coatings are examined by XRD, SEM, EDAX and microhardness measurements. However intermetallic phases were not found in mechanically alloyed powder, but coatings contained these phases. This shows that heat energy of plasma spray caused formation of NiAl phases during flying of particles to substrate or after reaching to substrate. Comparison of coatings properties indicated that mechanical alloying of powders caused improving mechanical properties and decreasing porosity percentage of coatings. Change of spray distance caused changing in phases, porosity percentage and microhardness of coatings. Best spray distance for spraying of the made powder determined as 11cm.

For production of intermetallic coatings, various types of Ni-Al powders were plasma sprayed at different spray distance and the effect of heat treatment on phases, microstructures and microhardness of coatings was examined. XRD, SEM, EDAX and microhardness were used for characterization of the coatings. Heat treatment of the coatings in various temperatures caused changes in hardness of the coating, increased percentage of intermetallic compounds, completed intermetallic production reactions, but did not change porosity percent. Increasing heat treatment temperature caused oxidation and decreased improvement of coating properties.