Deformation mechanisms in a WC–Co based cemented carbide during creep

• Published in: International journal of refractory metals & hard materials Vol. 49; no. 1; pp. 81 - 87
• Main Authors: Yousfi, M.A., Weidow, J., Nordgren, A., Falk, L.K.L., Andrén, H.-O.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2015
• Subjects: Binder phase morphology; Binders; Cemented carbides; Cobalt; Creep tests; Deformation; Dislocations; Grain growth; Grains; Linear intercept length; Plastic deformation; Strain; Tungsten carbide; Cemented carbides; Binder phase morphology; Plastic deformation; Grain growth; Linear intercept length; Dislocations
• ISSN: 0263-4368; 2213-3917; 2213-3917
• DOI: 10.1016/j.ijrmhm.2014.07.016

The microstructure of a WC–Co based cemented carbide has been investigated before and after plastic deformation at high temperatures. The material was fabricated with a Co binder phase content of 16vol.% and smaller additions of Cr. Hot compressive creep tests were performed under an applied load of 900MPa at 1000 and 1100°C. The test bars were deformed to 10 or 20% strain at 1000°C, and to 7% strain at 1100°C. Quantitative microscopy using SEM suggests that WC grain growth took place during the creep tests, and that the growth took place preferentially in the plane perpendicular to the load axis. TEM showed that there was an increased dislocation density in the WC grains after creep deformation. Deformation was also associated with a redistribution of the WC grains resulting in the formation of intergranular binder phase lamellae and cavities. EBSD showed that there was an increased spread in the crystallographic orientation of the binder phase after deformation.