Deformation and fracture processes and the physical metallurgy of WC–Co hardmetals

Fatigue of Cemented Carbides

“…From a testing perspective, Roebuck and coworkers have introduced the use of notched test pieces (Gee et al, 2009;Roebuck, 2002;Roebuck et al, 2008;Roebuck et al, 2009) as baseline for new testing protocols. The main reason for this is that interpretation of results from fatigue bend tests on smooth specimens suffers from the same (or even more) difficulties associated with conventional bend tests in that failures initiate at pores or other internal defects (Roebuck & Almond, 1988). Thus, intrinsic microstructural effects may be hindered by the influence of distribution and size of processing defects and/or the method of surface preparation on strength data.…”

“…Exner, 1979;Fischmeister, 1983;Gee, Gant, Roebuck, & K.P. Mingard, 2014;Gurland, 1988;Roebuck & Almond, 1988;Shatov, 2014), information on fatigue behavior is not as extensive.…”

Fracture and Strength of Hardmetals at Room Temperature

“…Changing the shape of WC crystals to flatter triangular prism for the fixed mlicc d WC (Shatov & Firstov, 1995;Shatov, Firstov, & Shatova, 1998) breaks the correlation versus the contiguity G, but preserves the Figure 5 Fracture toughness K 1C decreases with the increase of the hardness for conventional WC-Co hardmetals (reproduced from Figure 13 in Roebuck and Almond (1988) with permission from Maney Publishing www.maney.co.uk/journals/imr and www. ingentaconnect.com/content/maney/imr; Figure 8 in Jia, Fischer and Gallois (1998) with permission from Elsevier), but nanograined WC-Co with a variety of growth inhibitors promise higher fracture toughness at very high hardness (reproduced from Figure 8 in Jia, Fischer, and Gallois (1998) with permission from Elsevier; Figure 8 in Fang, Wang, Ryu, Hwang and Sohn (2009) with permission from Elsevier.)…”

“…Reproduced from Figure 11 in Roebuck and Almond (1988) with permission from Maney Publishing www.maney.co.uk/journals/imr and www.ingentaconnect.com/content/maney/imr.…”

Experimental and Thermodynamic Exploration of the High-Temperature Microstructures of Co-30 wt.% Cr- (2.5-5.0 wt.%) C Alloys

“…[3] Other cobalt alloys, not protected against wet or dry corrosion by such high chromium content, contain high quantities of carbon present as various carbides to take benefit of high hardness to resist wear. This is the case of cutting tools [4] made of a cobalt matrix containing high fractions of dispersed WC carbides, or wear-protective coatings [5] consisting in Co-W 2 C deposited by thermal spray on steels.…”