Diffusion Behaviour of the Grain-Growth Inhibitor Vc in Hardmetals

Abstract:

Diffusion couples of the type WC-Co/VC-Co were employed to observe the diffusion behaviour of the grain-growth inhibitor (GGI) VC within nanoand ultrafine-grained WC-10wt.% Co samples. Since diffusion of the GGI during heating occurs already in the solid-state regime, interrupted sintering experiments were performed up to the liquid phase formation temperatures. By the use of light-optical and scanning electron microscopy the impact of GGI concentration on the microstructure as a function of depth from the interface was investigated. Electron Probe Microanalysis (EPMA) was used in order to quantify the amount of vanadium diffused into WC-Co as a function of distance. In first approximation, an activation energy of 3.45 eV (332,6 kJ/mol) for vanadium transport was determined.

• Periodical: Defect and Diffusion Forum (Volumes 323-325)
• Pages: 509-514
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.323-325.509
• Online since: April 2012
• Authors: M. Brieseck, I. Hünsche, B. Caspers, G. Gille, M. Bohn, Walter Lengauer
• Keywords: Diffusion Couples, Doping, Grain Growth Inhibitor, Hardmetal, Tungsten Carbide, Vanadium Carbide

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