Consolidation mechanism, microstructural evolution and corrosion resistance of Inconel 625 coatings

ABSTRACT

The inter-relationships between geometrical properties, microstructural characteristics and corrosion resistance on one hand and laser-material interaction parameter (α) on the other hand are examined. A laser-material interaction parameter within the range of 599 ≤ α ≤ 400 J.s g⁻¹ mm⁻¹ imparted optimum characteristics of microstructure, microhardness and corrosion resistance. The consolidation mechanism of the coatings indicates that this parameter ensures the formation of a double ‘burn-in’ macrostructure into the substrate which imparts non-porous, crack-free and a fine interfacial microstructure. This study provides guidance in designing Inconel 625 coatings of desirable microstructures and corrosion resistance.

KEYWORDS:

• Laser cladding
• IPG YLS 5000 Fibre laser
• laser-materials interaction parameter
• Inconel 625 coatings
• corrosion resistance
• dilution
• microstructure evolution
• consolidation mechanism

Acknowledgements

This research is supported by the African Laser Center (ALC) under Grant no. CSIR-NLC Reference LHIL 500 task ALC R008 & R010) and Botswana International University of Science & Technology (BIUST) Research Initiation Fund under Grant no. BIUST/ds/r&I/7/2016. The authors are grateful to Mr. Samuel Skhosane for his assistance in operating the laser facility at CSIR, Pretoria, South Africa.

Disclosure statement

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

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

This work was supported by African Laser Centre, Council for Scientific and Industrial Research [grant number CSIR-NLC Reference LHIL 500 task ALC R007 & R014)]; Botswana International University of Science and Technology [grant number Research Initiation Fund under Grant no. BIUST/ds/r&I/7/2016].