Influence of Tantalum on phase stability and mechanical properties of WB2. (4th February 2019)

• Record Type: Journal Article
• Authors: Fuger, Christoph; Moraes, Vincent; Hahn, Rainer; Bolvardi, Hamid; Polcik, Peter; Riedl, Helmut; Mayrhofer, Paul Heinz
• Is Part Of: MRS communications. Volume 9:Number 1(2019)
• Page Start: 375
• Page End: 380
• Publication Date: 2019-02-04
• Subjects: Materials -- Periodicals; 620.11
• DOI: 10.1557/mrc.2019.5
• Languages: English
• ISSNs: 2159-6859

Abstract

Abstract: Abstract : Based on density functional theory, we recently suggested that metastable α -WB2 is a promising candidate combining very high hardness with high toughness. These calculations further suggested that the addition of Tantalum supports the crystallization of α -structured W1− x Ta x B2− z, with only minor reduction in toughness. Thus, various Ta containing WB2 -based coatings have been synthesized using physical vapor deposition. With increasing Ta content, the hardness increases from ~41 GPa (WB2 ) to ~45 GPa (W0.74 Ta0.26 B2 ). In situ micromechanical cantilever bending tests exhibit fracture toughness K IC values of 3.7 to 3.0 MPa√m for increasing Ta content (single-phased up to 26 at.% Ta).