Microstructure and Tribological Properties of Ni-Base Coatings under Different Lubrication Conditions

Abstract

In order to improve the tribological properties of aluminum alloy cylinder wall, Ni-base coatings were fabricated by atmospheric plasma spraying on aluminum substrate. The composition, microstructure characterization and tribological properties of Ni-base coatings were investigated under different lubrication conditions. The results showed that as-sprayed Ni-based coatings were mainly consisted of γ-Ni solid solution, Ni3B, Cr7C3, Cr6C and Cr3B2 phase. The microstructure of coatings exhibited excellent deposit integrity and density, whilst a typical lamellar structure was observed because the molten droplets successively impinged and spread on the substrate or previously deposited layers to form continuous splats. Friction and wear testing results showed that Ni-based coating performs better than grey cast iron HT200 for the actual application of cylinder block and cylinder liner, especially under boundary lubrication. It was proposed that the excellent mechanical properties ensure the as-sprayed coating with low friction coefficient and wear rate under different lubrication conditions, In addition, the existence of pores was benefitted for the improvement of tribological properties under boundary lubrication.

Tribocorrosion behaviors of thermal spraying WC/Ni60 coated 316L stainless steel in artificial seawater

“…Among those methods, thermal spraying is widely used in improving the strength, hardness and wear or corrosion resistance of metallic materials. In addition, our previous works prove that the thermal sprayed Ni-based coating possess better hardness, wear and corrosion resistance (Wang et al, 2015). Theoretically, the performance of 316 L in preventing tribocorrosion can also be improved by WC/Ni60 coating, which is mainly because that WC reinforcements perform well in hardness and Ni matrix possesses excellent corrosion resistance.…”

The Concept of WC-CrC-Ni Plasma-Sprayed Coating with the Addition of YSZ Nanopowder for Cylinder Liner Applications

“…In fact, different thermal spray processes such as wire arc spray, plasma transfer arc, atmospheric plasma spray, as well as HVOF were applied to the internal area of the cylinder liners [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Kincarid and Witherspoon [ 11 ] developed the pulse Arc-Spray for the production of Al and Fe-based alloys.…”

“…He proved that flow of primary plasma gas has a strong influence on wear resistance as well as on the friction coefficient. Wang et al [ 35 ] showed that the plasma spraying of nickel on aluminum cylinder liners decreased the friction coefficient without the necessity of a honing process. The surface finish by honing thermally sprayed coatings was investigated by Hoffmeister et al [ 36 ].…”