Tribological performance of thermally sprayed NiWCrBSi alloy coating by two different oxyacetylene flame stoichiometries

ABSTRACT

In the present work, the effects of oxidising and standard flame spray techniques on microstructure and wear performance of Low Velocity Oxygen Fuel NiWCrBSi coatings produced onto mild steel substrate were studied. Results showed that coating microstructure was dependent on the stoichiometry of the reacting gas mixture. Coatings produced in oxidising flame conditions showed higher amounts of semi-molten particles and high quantity of WC phases. Those coatings showed a good behaviour in dry sliding wear test, due to their higher hardness and the formation of compact and adherent oxide tribofilms. The wear behaviour of non-molten particles against friction forces is discussed, with the aim of establishing relationships between the tribological response of the material and its process-induced microstructure defects.

KEYWORDS:

• NiWCrBSi
• flame spray coatings
• microstructure
• oxidising/standard flame
• wear

Acknowledgements

The authors are grateful and wish to express their thanks to the SNC ATRA Oultache company (Bejaia, Algeria) for carrying out the Ni-based coatings deposition. The authors also wish to express their thanks to Djellal Naçira, PhD student (laboratory L3M-ENSMM, University of Annaba, Algeria) for her help in the mechanical and tribological characterisation of the coatings.

Disclosure statement

No potential conflict of interest was reported by the author(s).