High-temperature wear behaviour of HVOF sprayed 65% (NiCrSiFeBC)−35% (WC–Co) coating

ABSTRACT

The aim of the current investigation was to study the high-temperature tribological performance of the high-velocity Oxyfuel sprayed 65% (NiCrSiFeBC)−35%(WC–Co) coating at the temperatures ranging from room temperatures to 800°C. The coating was produced on the hot forming die steels namely AISI H11 and AISI H13. The microstructural characteristics, surface roughness, microhardness, porosity and bond strength of the as-sprayed coatings were determined. Tribology study was done on the pin-on-disc tribometer at 0.5 m s⁻¹ sliding velocity under the loads of 25N and 50N. The results have shown that the developed coating exhibited lower porosity, higher microhardness and performed much better than the uncoated specimens. The wear mechanisms of the coated specimens were mainly abrasive at room temperatures. Adhesive and oxidative wear were observed as the dominant mechanisms at the elevated temperatures.

KEYWORDS:

• Hot forming steels
• HVOF spray
• 65%(NiCrSiFeBC)-35%(WC–Co) coating
• high-temperature wear
• SEM

Acknowledgement

The authors thankfully acknowledge the research grant from Department of Science and Technology, New Delhi (India) under SERB, Science and Engineering- Engineering Scheme (File No. SR/S3/MERC/0072/2012, Dated February 28, 2013) titled-Development of Thermal Spray Coatings to Control Wear during High-Temperature Applications, and (EMR/2015/000234, Dated March 11, 2016) titled-Development of Thermal Spray Coatings to Control Wear during High-Temperature Applications-Phase II, to carry out this research and development work, Moreover, the authors would like to thank the Metallising Equipment Company Pvt. Ltd. Jodhpur (India) for providing The HVOF and Plasma spray coatings services for the die materials. The authors owe special thanks to Dr Harpreet Singh for extending the necessary facilities and support in conducting the detailed analysis at Indian Institute of Technology Ropar, Roopnagar, Punjab, and Dr S. Parkash at Indian Institute of Technology Roorkee, Roorkee. The authors would also like to thank IKGPTU, Jalandhar, India for supporting this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Science and Engineering Research Board: [grant number EMR/2015/000234, Dated 11 March 2016 SR/S3/MERC/0072/2012, Dated 28 February 2013].