Release Time:2019-07-01  Hits:

Indexed by: Journal Article

Date of Publication: 2019-06-01

Journal: MATERIALS LETTERS

Included Journals: EI、SCIE

Volume: 244

Page Number: 207-210

ISSN: 0167-577X

Key Words: Graphite nanospheres; Non-equilibrium process; Composite materials; Surfaces

Abstract: Understanding the formation mechanism of graphite nanospheres (GNS) in W-C-Co system under high current pulsed electron beam (HCPEB) irradiation is necessary for its application on surface modification of WC-Co cemented carbide. With this aim, XRD, SEM, EDS and TEM were used to investigate the effect of HCPEB irradiation on surface microstructure and phase composition. Results showed the micro-WC grains and Co were melted and transformed into nano-grained composite structure in the surface layer similar to 1.29 mu m. Two general scales of GNS were discerned in two types of element composition ambiences, i.e. similar to 100 nm in Co-rich region and similar to 50 nm in Co-poor region. Thermodynamic analysis suggested that they were the results of different routes in the non-equilibrium melting and re-solidification process. (C) 2019 Elsevier B.V. All rights reserved.