Effect of Substrate Type on Deposition Behavior and Wear Performance of Ni-Coated Graphite/Al Composite Coatings Deposited by Cold Spraying

This work focused on the deposition characteristics and wear behavior of Ni-coated graphite mixed with 40 vol.% Al (Ni-Gr/Al) composite coatings sprayed on an Al alloy and a steel substrate by cold spraying (CS). The morphology of the flattened Ni-Gr particles was examined by single-impact tests. Cross-sectional microstructure and wear performance of the Ni-Gr/Al composite coatings were studied. Results showed that a larger number of Ni-Gr particles were finally bonded with the steel substrate, whereas many craters existed on the Al alloy substrate after the single-impact tests. The coating on the steel substrate had a high thickness, high graphite content and low coefficient of friction (COF) compared to those on the Al alloy substrate. In addition, the CS coatings presented a homogeneous distribution and uniform morphology of graphite, and a comparative COF to that of conventional thermal sprayed coatings. It was shown that CS could avoid the decomposition and transformation of graphite phase. Copyright (C) 2017, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited.