High Temperature Oxidation of Nickel-based Cermet Coatings Composed of Al2O3 and TiO2 Nanosized Particles

Abstract

New technological challenges in oil production require materials that can resist high temperature oxidation. In-Situ Combustion (ISC) oil production technique is a new method that uses injection of air and ignition techniques to reduce the viscosity of bitumen in a reservoir and as a result crude bitumen can be produced and extracted from the reservoir. During the in-situ combustion process, production pipes and other mechanical components can be exposed to air-like gaseous environments at extreme temperatures as high as 700 °C. To protect or reduce the surface degradation of pipes and mechanical components used in in-situ combustion, the use of nickel-based ceramic-metallic (cermet) coating produced by co-electrodeposition of nanosized Al 2 O 3 and TiO 2 have been suggested and earlier research on these coatings have shown promising oxidation resistance against atmospheric oxygen and combustion gases at elevated temperatures. Co-electrodeposition of nickel-based cermet coatings is a low-cost method that has the benefit of allowing both internal and external surfaces of pipes and components to be coated during a single electroplating process. Research has shown that the volume fraction of dispersed nanosized Al 2 O 3 and TiO 2 particles in the nickel matrix which affects the oxidation resistance of the coating can be controlled by the concentration of these particles in the electrolyte solution, as well as the applied current density during electrodeposition. This paper investigates the high temperature oxidation behaviour of novel nanostructured cermet coatings composed of two types of dispersed nanosized ceramic particles (Al 2 O 3 and TiO 2 ) in a nickel matrix and produced by coelectrodeposition technique as a function of the concentration of these particles in the electrolyte solution and applied current density. For this purpose, high temperature oxidation tests were conducted in dry air for 96 hours at 700 °C to obtain mass changes (per unit of area) at specific time intervals. Statistical techniques as described in ASTM G16 were used to formulate the oxidation mass change as a function of time. The cross-section and surface of the oxidized coatings were examined for both visual and chemical analyses using wavelength dispersive x-ray spectroscopy (WDS) element mapping, X-ray Diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDS). The results showed that the volume fraction for each type of particle in the nickel matrix corresponded to its partial molar concentration in the electrolyte solutions. Increase in volume fraction of particles in the nickel matrix was correlated to lower oxidation rates. It was concluded that formation of Ni 3 TiO 5 and NiTiO 3 compounds can reduce the oxidation rate of cermet coatings by capturing some inward diffusing oxygen ions resulting in a lower number of nickel cations diffusing upward into the oxide layer.

Microstructure and High Temperature Corrosion Behavior of Wire-Arc Sprayed FeCrSiB Coating

“…High temperature oxidation and corrosion are recognized as being the main reasons of massive degradation of components, which are used in aggressive high temperature environments, such as metallurgical furnaces, coal-fired boilers, and industrial solid waste incinerators (Ref [1][2][3][4]. The leakage of these components can lead to the operating risks and costly shutdowns.…”

Wear and high temperature oxidation behaviour of wire arc sprayed iron based coatings

“…[1][2][3][4] The leakage of these components may cause the increase in operating risks and costly shutdowns. One of the potential methods to overcome these problems is the deposition of thermally sprayed coatings, which can be prepared by various thermal spraying techniques, [5][6][7][8][9][10] Among the spraying techniques, wire arc spraying has attracted special interest due to its economical efficiency.…”