Influence of the adhesion of coatings applied by different thermal spray processes on their wear and corrosion properties

Abstract

Thermal spray technology has gradually achieved great prestige in the industrial and scientific environment, leading it to a technological and commercial prominent position in diverse and high-tech sectors such as aerospace, biomedical engineering, automotive, energy, oil & gas, among others. The research and development activities relating to thermal spraying technology has been intense worldwide, resulting in new possibilities and engineering alternatives such as the use of coatings to replace environmentally harsh processes, protection of equipment for nuclear fusion, extraction of oil and gas, and coatings for surgical implants. The increasing diversification and improvement of processes and materials for specific applications is expanding coatings project development capacity for specific service conditions, yielding surfaces resistant to heat, wear, erosion, corrosion, as well as unique combinations of these properties. Whatever the application of coatings, two properties are of supreme importance, i.e., wear resistance and especially the adhesion of coatings to substrates which define the effective durability and performance of the coatings. In this project, we intend to evaluate such properties and their correlation in coatings applied by different thermal spray processes, namely: Flame Spray, Arc Spray and HVOF - High Velocity Oxygen Fuel. Different materials will be tested by these processes in adhesion tests (ASTM C633-01), wear resistance (ASTM G65-03) and erosive wear (non-standard). Optical microscopy (OM) and scanning electron microscopy (SEM), measurement of Vickers hardness and surface roughness will be accomplished to help in the coatings analysis and understanding of microstructure and morphology changes. (AU)