Preparation of ultrafine WC-Co cermets by combining pretreatment and consolidation with spark plasma sintering

Zhao, Shixian; Song, Xiaoyan; Wang, Mingsheng; Liu, Guoquan; Zhang, Jiuxing

doi:10.1007/s12598-009-0077-4

Cited by 9 publications

(2 citation statements)

References 16 publications

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“…The reported values for SPS-sintered WC-Co appeared to follow the same trend, ranging from 1100 to 3100 MPa when considering hardness. [32][33][34] Thus, flexural fracture strength is often thought to be inversely related to hardness and this work also shows the same pattern.…”

Section: Mechanical Propertiessupporting

confidence: 71%

Preparation of High‐Performance WC–MgO Composites by Spark Plasma Sintering

et al. 2022

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Herein, tungsten carbide (WC)–4.3 wt% MgO composite powders are synthesized by high‐energy planetary ball milling method and then consolidated by spark plasma sintering (SPS). Submicrometer WC–MgO composite powders are consolidated to obtain a nearly complete density of WC–MgO composites (99.15%). The nanosized MgO distributed along the WC grains in WC–MgO composite plays an important role of dispersion strengthening and achieving high flexural fracture strength of WC–MgO composites (1348 MPa). As the addition of MgO increases the interfacial strength, the fracture mode of WC–MgO composites is mainly a mixture of transgranular fracture and intergranular fracture. High value on Vickers hardness (1660HV) and fracture toughness (9.37 MPa m1/2) of WC–MgO are also observed due to the crack deflection and crack bridging. Binderless WC–MgO composites have similar properties to WC–Co and are expected to replace WC–Co hard metal for saving resources and reducing cost.

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Section: Mechanical Propertiessupporting

confidence: 71%

Preparation of High‐Performance WC–MgO Composites by Spark Plasma Sintering

et al. 2022

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“…Note that powders with an increased carbon content sinter faster [69,72], while an increased concentration of tungsten in cobalt leads to the lower plasticity of cobalt and a lower intensity of η-phase spreading between α-WC particles [18,19]. Some of the cited papers [20][21][22] suppose that the concentration of carbon may have a strong impact on the diffusion creep of the η-phase, which can control the intensity of shrinkage at early sintering stages in WC-Co hard alloys. The oxygen/carbon ratio in the powders was shown to be important for high density, microstructure uniformity, and high mechanical properties of the hard alloys.…”

Section: Introductionmentioning

confidence: 99%

A Study of the Impact of Graphite on the Kinetics of SPS in Nano- and Submicron WC-10%Co Powder Compositions

et al. 2021

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This study investigates the impact of carbon on the kinetics of the spark plasma sintering (SPS) of nano- and submicron powders WC-10wt.%Co. Carbon, in the form of graphite, was introduced into powders by mixing. The activation energy of solid-phase sintering was determined for the conditions of isothermal and continuous heating. It has been demonstrated that increasing the carbon content leads to a decrease in the fraction of η-phase particles and a shift of the shrinkage curve towards lower heating temperatures. It has been established that increasing the graphite content in nano- and submicron powders has no significant effect on the SPS activation energy for “mid-range” heating temperatures, QS(I). The value of QS(I) is close to the activation energy of grain-boundary diffusion in cobalt. It has been demonstrated that increasing the content of graphite leads to a significant decrease in the SPS activation energy, QS(II), for “higher-range” heating temperatures due to lower concentration of tungsten atoms in cobalt-based γ-phase. It has been established that the sintering kinetics of fine-grained WC-Co hard alloys is limited by the intensity of diffusion creep of cobalt (Coble creep).

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