Influence of temperature, grain size and cobalt content on the hardness of WC–Co alloys

Milman, Yu.V.; Luyckx, S.; Northrop, I.T.

doi:10.1016/s0263-4368(98)00038-9

Cited by 123 publications

(40 citation statements)

References 3 publications

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“…The sintering process was carried in vacuum or N 2 /H 2 mixed gas atmosphere at 1380°C. In general, the cemented carbides based on WC-Co are processed by the liquid-phase sintering of compacted powder mixture of WC and Co. WC-Co hard materials can be densified by liquid phase sintering and the mechanical properties of these materials depend on their composition and microstructure (particularly the average size and size distribution of WC grains) [7,8].…”

Section: Methodsmentioning

confidence: 99%

The effect of sintering conditions on the properties of WC–10wt%Co PIM compacts

Choi

Kang

Kwon³

et al. 2010

Res Chem Intermed

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The powder injection molding (PIM) process has an advantage of near net shaping of homogeneous micro structure and density at the complicate form. This study was investigated for microstructure and mechanical properties of WC10%Co insert tool alloy fabricated by PIM process. The WC-10%Co feedstock mixed with wax binder was fabricated by two blade mixer. After WC-10%Co feedstocks were injection molded, debinding process was carried by two-steps methods with solvent extraction and thermal debinding. The binder was eliminated with normal hexane for 12 h at 50°C by solvent extraction, and subsequently thermal debinding was examined for 1 h at the temperature 900°C. After debinding process, the specimens were sintered at vacuum or N 2 /H 2 mixed gas atmosphere at 1380°C. The microstructure and phase were observed by FE-SEM. In the case of sintered at 1380°C in vacuum atmosphere, the hardness was 1600 Hv, and the relative density of WC-10%Co was 92.5%. The density of WC-10%Co sintered at 1380°C in mixed gas atmosphere was 87.5% and the hardness was lower than 1400 Hv. Residual carbon contents of sintered at vacuum and mixed gas atmosphere were 5.4 wt%.

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Section: Methodsmentioning

confidence: 99%

The effect of sintering conditions on the properties of WC–10wt%Co PIM compacts

Choi

Kang

Kwon³

et al. 2010

Res Chem Intermed

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“…The performance of the CC depends on different parameters, such as, WC grain size, amount of binder (cobalt) content, carbon content, and presence of porosity [8]. Milman et al (1999) have concluded that presence of fine WC grain makes the CC very hard and wear resistant [33]. It has been reported that an increase in the cobalt content reduces hardness [10] and increases transverse rupture strength [8] of the CC.…”

Section: Literature Surveymentioning

confidence: 99%

MICROSTRUCTURAL STUDY OF FAILURE PHENOMENA IN WC 94%-Co 6% HARD METAL ALLOY TIPS OF RADIAL PICKS

Nahak¹,

Chattopadhyaya²,

Dewangan

et al. 2017

Adv. Sci. Technol. Res. J.

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An excellent combination of hardness, strength, stiffness and high melting point has proved the WC-Co as an ideal material for tools that are used for metal cutting, coal mining, oil drilling, etc. The ongoing research in WC-Co is focussed on enhancing its wear resistant properties as much as possible. For the purpose, many attempts have been made to study the tribological behaviour of WC-Co for a long time. Researchers have used various grades of WC-Co in different working environments and accordingly they have characterized the wear phenomena involved there within. In this direction of research, the present paper makes an attempt to understand various wear behaviours in WC 94%-Co 6% hard metal alloy. WC-Co was used as a tip of the coal cutting tool named radial pick. Two radial picks have been taken for critical analysis through field emission scanning electron microscopy (FESEM) attached with energy dispersive Xray spectroscopy (EDS). In this work, the failure behaviours in the tools have been divided into five categories: (1) Abrasion on individual grain; (2) Corrosion in carbide grains; (3) Fragmentation and removal of WC grains; (4) Pores in WC grains; and (5) Coal and rock embedding. The most possible reasons behind each failure phenomenon have been explained comprehensively with the help of high-resolution microscopic images. However, it is usually observed that, initially, the tool gets minor cracks due to sudden impact. These cracks provide a path to the rock and coal particles to get entrenched inside the microstructure of cemented carbide. Finally, the intermixed external elements degrade the binder content (i.e. cobalt) and the tool becomes useless.

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“…Therefore, only in this case, the mlicc d WC is proportional to l according to the stereological relation (22) and the LG model (46) can be reduced to the single dependence on the mlibp l similar to the hardness dependence on d WC in the LG model for the fixed volume fraction V V (Cha, Hong, Ha, & Kim, 2001;Jeong, Kim, Doh, et al, 2007;Kim, Massa, & Rohrer, 2007;Lee, Cha, Kim, & Hong, 2006;Milman, Chugunova, Goncharuck, Luyckx, & Northrop, 1997;Milman, Luyckx, & Northrop, 1999;Roebuck, 1995;. As soon as the volume fraction V V changes, a more complex dependence of the yield stress s y on all the microstructure parameters should be used instead as it is shown in the LG model for the hardness (46) (Gurland, 1979;Lee & Gurland, 1978).…”

Section: Armstrong and Cazacu (Ac) Model Based On Strength To Yield Smentioning

confidence: 99%