Performance of Ni-Based Coatings with Various Additives Fabricated by Cold Gas Spraying

Abstract

The complexity of the operating conditions in oil fields requires the development and use of materials with unique properties. This paper presents the study results for nickel-based coatings fabricated by cold gas spraying. In this study, compositions based on Ni, Ni-Cu, Ni-Zn, Ni-Al2O3/TiC coatings applied to low-alloyed steel bases were investigated. Corrosion resistance was studied by means of electrochemical autoclave testing in simulated oilfield conditions. Hydroabrasive resistance was studied using a unique testing bench. Scanning electron microscopy mappings, microhardness testing, and adhesion testing were used to correlate the results of the tests with the structure, continuity, and porosity of the studied coatings. All the studied coating specimens had a sufficiently high adhesion. The Ni-Zn coating exhibited the lowest corrosion resistance and high hydroabrasive resistance. The Ni-Cu coatings exhibited a high degree of corrosion. The Al2O3/TiC additives gave ambiguous results with respect to the studied properties. Thicknesses of 40–60 microns provided acceptable performance for the studied coatings. Thus, varying the chemical composition the thickness of coatings allows optimal qualities to be obtained for Ni-based coatings made by cold gas spraying for use in the oil and gas industry.