A comparative assessment on the characteristics of HVOF sprayed cermet coatings

ABSTRACT

High Velocity Oxygen Fuel (HVOF) process enables superior properties and is foreseen as a suitable candidate for deposition of hard chromium alternative coatings over the other surface hardening techniques like cladding/deposition through electrolysis/CVD methods, owing to the widespread adaptability and preference in aerospace industry, in particular landing gear mechanism and associated modules that operating in severe environments encountering abrasion, erosion, sliding and fretting wear. Cermet coatings are very often utilised to intensify the wear and corrosion resistance of a wide range of engineering components. The objective of this work is to develop thermally sprayable oxides, nitrides and carbides of WC and Cr₃C₂ cermet coatings on AISI 4340 steel by HVOF technique. The modified surface is characterised by SEM/EDAX study, followed by the evaluation of Porosity and Microhardness of the modified different speeds and loads. The study unveiled that of all the stated coatings, the blend of WC-Co-VC matrix yields superior hardness, Coefficient of friction and lower order of porosity. The observation forefronts the enhancement of wear properties in terms of surpassing wear resistance and declining trend in volume loss compared to other compositions.

KEYWORDS:

• Cermet
• HVOF
• wear
• corrosion
• micro hardness
• porosity

Disclosure statement

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

Data availability statement

Manuscript has no associated data.

Additional information

Notes on contributors

G. Padmavathi

G. Padmavathi is currently serving in Dayananda Sagar College of Engineering, Bengaluru, as Assistant Professor in the Dept of Mechanical Engineering. Her research area includes surface coatings and composite materials

B. N. Sarada

B. N. Sarada, working as Professor at B.M.S College of Engineering, Bengaluru, in the Dept of Mechanical Engineering. Her research area includes Materials and Metallurgy.

S.P. Shanmuganatan

S.P. Shanmuganatan, currently serving as Associate Professor at Dayananda Sagar College of Engineering in Mechanical Engineering Dept, Bengaluru. His research area includes metal forming, friction Stir welding and processing

H. Ramesha

H. Ramesha, working as Associate Professor at Dayananda Sagar college of Engineering, in Mechanical Engineering Dept Bengaluru. His research area includes Finite element modelling, Composites.

B.V. Padmini

B.V.Padmini, assistant professor, Sambhram Institute of Technology, Bengaluru, in Mechanical Engineering Dept. Her research area includes Thermal spray coatings and composites.

R. Krishnamurthy

R. Krishnamurthy, professor(retired) Indian Institute of Technology, Chennai. His research area includes metal cutting, tribology and composites.