Reliability is one of the most important requirements for electric motor installations. Bearing assembly is a common source of failure for most electric motors. One of the main reasons for such failures is the wear of the bearing seat of the end shield. This paper presents a combined technology for increasing the durability of the bearing bores of electric motor bearing shields made of aluminum alloys. The technological concept is that a worn-out end-shield bore is firstly restored by supersonic gas-dynamic spraying, and secondly, in order to improve anti-wear properties, it is strengthened by micro-arc oxidation. The adhesion of coatings has been studied, and the wear resistance of the formed coatings has been evaluated. Based on the performed studies, it can be assumed that the service life of the bearing assembly of an electric motor restored by gas-dynamic spraying with the novel technology of micro-arc oxidation in real operating conditions will increase on average by 3–4 times. The developed technology is recommended for repair, maintenance, or other technical services dealing with the restoration and hardening of worn-out parts.

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.

This paper presents the results of the study of nickel-based coatings fabricated by cold gas spraying. In this study, compositions based on Ni, Ni–Cu, Ni–Zn, and Ni–Al₂O₃/TiC coatings applied to low-alloyed steel bases were investigated. The composition, type of powder (mechanical mix or mechanically alloying), and thickness varied to choose the optimal characteristics for recovery, repair procedures, and specific applications in the oil and gas industry media. The second phase was added to Ni-based coatings to increase corrosion and wear resistance. Pure nickel coatings were also studied as a benchmark. Corrosion resistance was studied by means of electrochemical testing and 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. It was shown that applying mechanical alloying of the powder did not lead to an effective increase of corrosion and hydroabrasive resistance. All the studied coating specimens have a sufficiently high adhesion. Ni–Zn coating has the lowest corrosion resistance and high hydroabrasive resistance. Ni–Cu coatings have high corrosion and the lowest hydroabrasive resistance. Al₂O₃/TiC additives give ambiguous results in the studied properties. A thickness of 40–60 microns provides sufficient performance of the studied coatings. Thus, varying chemical composition and thickness of coatings allows for obtaining the optimal qualities of Ni-based coatings made by cold gas spraying for use in the oil and gas industry.