On the mechanism of WC coarsening in WC–Co hardmetals with various carbon contents

Some aspects of the structure of cobalt and nickel binder phases in hardmetals

“…In the alloys examined in this study, the W content varied from 3 wt.% (1 at.%) up to 8.2 wt.% (2.6 at.%). The grain size variation is largely consistent with this [29], with larger sizes in the low W content alloys, but there is no trend with Co structure; the lowest W content alloys S16A and 11D have a mixed hcp/fcc structure, the intermediate W content alloys an almost fully fcc structure and the highest hcp content occurs in the highest W content alloy 6C which is very close in composition to the fully fcc S10A.…”

Cemented Carbides for Mining, Construction and Wear Parts

“…The results mentioned above should be considered more carefully when taking into account recent results of Konyashin et al (2009) on the dependence of the WC recrystallization rate during liquid-phase sintering of cemented carbides on the carbon content. It was found that even within the two-phase region, the recrystallization rate of fine WC fraction in the alloy with low carbon content is about six times lower than that in the alloy with high carbon content.…”

“…Therefore, cemented carbides for mining and construction should be produced with high carbon contents to minimize the risk of the h-phase formation. (2) According to Cho, Chung, and Lee (1999), Konyashin et al (2009), Konyashin et al (2010), when producing coarse-or ultra-coarse-grain cemented carbides with low carbon contents, the fine-grain WC fraction formed as a result of milling does not recrystallize on coarse WC grains leading to a noticeably reduced WC mean grain size. This results in a lower fracture toughness of the cemented carbides with the low carbon content, so that the carbon content in cemented carbides for mining and construction should be high to allow the fine-grain fraction to fully recrystallize on large WC grains.…”

Influences of the preparation methods of WC–Co powders on the sintering and microstructure of coarse grained WC–8Co hardmetals

“…However, the abnormal growth of WC grain is prone to occur in high temperature [10]. Although the addition of cubic carbides (VC, Cr 3 C 2 , NbC, TaC, TiC) can inhibit the growth of WC grain and improve the homogeneity of WC-Co microstructure [6], the addition of cubic carbides leads to the sacrifice of toughness and densification of WC-Co hardmetals [11,12].…”