Next Article in Journal
Evaluation of Accelerated Ageing Tests for Metallic and Non-Metallic Graffiti Paints Applied to Stone
Previous Article in Journal
Aluminum Templates of Different Sizes with Micro-, Nano- and Micro/Nano-Structures for Cell Culture
Article Menu
Issue 11 (November) cover image

Export Article

Open AccessArticle
Coatings 2017, 7(11), 178; https://doi.org/10.3390/coatings7110178

Evolution of Nanostructure and Metastable Phases at the Surface of a HCPEB-Treated WC-6% Co Hard Alloy with Increasing Irradiation Pulse Numbers

1
School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
2
Key Laboratory of Materials Modification & School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China
3
College of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, China
4
Laboratoire d’Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine, CNRS UMR 7239, Ile du Saulcy, 57045 Metz, France
*
Authors to whom correspondence should be addressed.
Academic Editor: Alessandro Lavacchi
Received: 30 July 2017 / Revised: 7 October 2017 / Accepted: 17 October 2017 / Published: 26 October 2017
View Full-Text   |   Download PDF [5056 KB, uploaded 27 October 2017]   |  

Abstract

This work investigates the mechanisms of the microstructure evolution in the melted surface layers of a WC-6% Co hard alloy when increasing the number of pulses of irradiation by high-current pulsed electron beam (HCPEB) treatment. After one pulse of irradiation, about 50% of the stable hcp WC phase was melted and resolidified into the metastable fcc form (WC1−x). When increasing the numbers of pulse irradiation, the WC phase decomposed into ultrafine-grained WC1−x plus nanosized graphite under our selected energy condition. Because of the rapidity of HCPEB carried under vacuum, the formation of the brittle W2C phase was avoided. In the initial Co-rich areas, where the Co was evaporated, melting and solidification led to the formation of nanostructures Co3W9C4 and Co3W3C. The volume fraction of the nano domains containing WC1−x, Co3W9C4, and Co3W3C phases reached its maximum after 20 pulses of irradiation. The improved properties after 20 pulses are therefore due to the presence of nano graphite that served as lubricant and dramatically decreased the friction coefficient, while the ultrafine-grained carbides and the nano domains contribute to the improvement of the surface microhardness and wear resistance. View Full-Text
Keywords: high current pulsed electron beam (HCPEB); WC-Co; rapid solidification; nanostructure high current pulsed electron beam (HCPEB); WC-Co; rapid solidification; nanostructure
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zhang, Y.; Yu, F.; Hao, S.; Dong, F.; Xu, Y.; Geng, W.; Zhang, N.; Gey, N.; Grosdidier, T.; Dong, C. Evolution of Nanostructure and Metastable Phases at the Surface of a HCPEB-Treated WC-6% Co Hard Alloy with Increasing Irradiation Pulse Numbers. Coatings 2017, 7, 178.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Coatings EISSN 2079-6412 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top