Tribological effects of the geometrical properties of plasma spray coatings partially melted by laser

• Published in: Wear 2013-07, Vol.305 (1-2), p.1-7
• Main Authors: García, A., Cadenas, M., Fernández, M.R., Noriega, A.
• Format: Article
• Language: English
• Subjects: Angles (geometry); Applied sciences; Carbon dioxide lasers; Contact melting; Contact of materials. Friction. Wear; Exact sciences and technology; Hardness; Laser processing; Lasers; Lubricated wear; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Ni alloys; Production techniques; Spray coating; Surface treatment; Thermal spray coatings; Tribology; Wear rate; Wear tests
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2013.05.004

The tribological behaviour of NiCrBSi plasma spray coatings partially melted by laser was investigated. Partial melting provides dual property surface coatings: melted areas, with a homogenous microstructure; and plasma spray areas, with porosity and cracks. This paper studies the influence of two geometrical properties of the partially melted surfaces: the angle of the laser tracks, and the ratio of the melted surface. Laser melting was performed using a 1700W CO2 laser and wear tests were carried out using a block-on-ring tribometer in pure sliding lubricated contact. The main wear mechanism and the interaction of the geometrical properties of the coating are discussed in this paper. The results of wear tests indicate that the best percentage of melted surface to reduce the wear rate is 46%, whereas the track angle is not found to be a major factor influencing the wear rate. The study of Coefficient of Friction (COF) reveals that low track angles have the lowest friction and that the percentage of melted surface is not a major factor influencing the COF. •Influence of two geometrical parameters on tribological behaviour was studied.•Pure sliding wear tests at lubricated contact were performed.•Partial melting process reduces wear, 46% of melted surface produces minimum wear.•Partial melting process increases COF, as greater track angle, greater COF.