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Indexed by:期刊论文

Date of Publication:2014-03-15

Journal:SURFACE & COATINGS TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:242

Page Number:14-19

ISSN No.:0257-8972

Key Words:Borides; Amorphous materials; Thin film; Hardness; Cluster-plus-glue-atom model

Abstract:obtain protecting thin films with excellent comprehensive properties, B-rich B-C-Mg amorphous thin films were designed using the cluster-plus-glue-atom model and then fabricated through magnetron sputtering technique. A type of cluster formula [B-(B6-x/2Cx/2)](B6-x/2Mgx/2)(X <= 2), that contains 24 valence electrons per unit cluster formula, was derived from relevant crystalline borides B12C2Mg and B7Mg. Amorphous and amorphous/nanocrystal thin films covering roughly a composition range formulated by [B-B5C]Mg (x = 2) similar to [B-BS.5C0.5]B0.5Mg0.5 (x = 1), prepared by magnetron sputtering, show increasing hardness, elastic modulus, toughness and coefficient of friction with increasing boron contents. The amorphous thin film corresponding to the critical of cluster formula, [B-B5C]Mg (x = 2), can probably be a good protective coating material for its relatively high hardness, about 24 GPa, and a fairly low coefficient of friction, about 0.05 (in air at room temperature, load 5N, Si3N4 ball as the counterpart). In addition, amorphous/nanocrystal sample B85.1C8.7Mg6.2 possesses a high hardness of 34 GPa in combination with a toughness of 3 MPa*m(1/2), being comparable to that of nc-TiN/SixN nanocomposite. (C) 2014 Elsevier B.V. All rights reserved.