The improvement of wear and corrosion resistance of nickel-graphite coating with modified graphite phase size

• Published in: Surface & coatings technology Vol. 485; p. 130906
• Main Authors: Yu, Fangli, Tang, Jianjiang, Zhang, Haihong, Zhang, Long, Zhang, Kuo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2024
• Subjects: Abradable coatings; Corrosion resistance; Friction and wear properties; Lubrication phase; Nickel-graphite; Corrosion resistance; Friction and wear properties; Abradable coatings; Nickel-graphite; Lubrication phase
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2024.130906

The corrosion resistance, friction and wear properties of an abradable seal coating are highly dependent on the size and distribution of lubrication phase. In this work, nickel-graphite (Ni-G) coatings were fabricated by a supersonic atmospheric plasma spraying system (SAPS) and a standard atmospheric plasma spraying system (APS), respectively. The effect of size and distribution of graphite phase on the performance of Ni-G coatings was investigated. The results suggested that the SAPS coating had an average single graphite phase area of 35.4 ± 5.1 μm2, which is approximately 35.4 % less than that of the APS coating, while the average graphite phase width and length in SAPS coating decreased by 22.2 % and 16.7 % compared to the APS coating. The fine distributed graphite phase improved the formation of structure with a small cathode and a large anode, which effectively increased the corrosion resistance of SAPS coating. The reciprocating sliding friction facilitated the creation of a uniform and uninterrupted lubricant layer, attributed to the finely dispersed graphite phase of SAPS coating. In comparison to the as-sprayed and subsequent corroded APS coatings, the friction coefficients of the SAPS coating exhibited a reduction of approximately 9.1 % and 13.3 %, respectively. The aforementioned findings showed that the small-sized graphite phase was conductive to the improvement of corrosion resistance, friction and wear properties of Ni-G abradable coatings. •Small cathode and large anode of Ni-G coatings can reduce corrosion damage of structure.•Refinement of graphite phase is beneficial to improve corrosion resistance of Ni-G coatings.•Uniform distribution of graphite helps to form lubricating film and improve wear resistance.