Wear-resistance and hardness: Are they directly related for nanostructured hard materials?. (March 2015)

• Record Type: Journal Article
• Authors: Konyashin, I.; Ries, B.; Hlawatschek, D.; Zhuk, Y.; Mazilkin, A.; Straumal, B.; Dorn, F.; Park, D.
• Is Part Of: International journal of refractory metals & hard materials. Volume 49(2015:Mar.)
• Page Start: 203
• Page End: 211
• Publication Date: 2015-03
• Subjects: Wear-resistance -- Hardness -- Fracture toughness -- Nanograin -- Nanoparticles -- Nanostructured hard materials; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2014.06.017
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: The major challenge in the field of cemented carbides and other hard materials is to obtain their better combination of hardness, wear-resistance and fracture toughness. It is well known that the dependence of abrasion wear on fracture toughness for WC–Co cemented carbides is represented by a relatively narrow band and it is hardly possible to "break away" out from it by the use of conventional approaches based on varying the WC mean grain size and Co content. Also, it is well known that the wear-resistance of conventional cemented carbides depends mainly on their hardness. The major objective of this paper is to establish what will happen with the wear-resistance of hard materials as a result of their nanostructuring when the hardness is nearly the same as for conventional WC–Co cemented carbides. The results obtained provide clear evidence that, if one enters the region of nanostructured materials with the mean grain size of less than 10 nm, traditional wisdom indicating that the wear-resistance is directly related to the hardness appears not to be valid. In some cases of such nanostructured materials, it can be possible to achieve the dramatically improved wear-resistance compared to that of conventional WC–Co cemented carbides at nearly the same level of hardness and fracture toughness. The abovementioned is based on considering hard nanomaterials of the following four types: (1) WC–Co cemented carbides with nanograin reinforced binder, (2) near-nano WC–Co cemented carbides, (3) cemented carbides of the W–C–Cr–Si–Fe system for hard-facing having a nanostructured Fe-based binder, and (4) CVD hard materials consisting of nanostructured W2 C grains embedded in a tungsten metal binder. Highlights: Wear-resistance of nanostructured hard materials is examined Wear-resistance of coarse cemented carbides is improved due to binder nano-reinforcement Wear-resistance of near-nano carbides is comparable with conventional WC-Co materials Wear-resistance of carbide hard-face materials is improved due to binder nanostructuring Wear-resistance of nanostructured CVD W2C-W coatings is comparable with WC-Co materials