Mechanisms of plastic deformation of WC-Co and Ti(C,N)-WC-Co
Journal article, 2006

The deformation of the cutting edge of inserts made from WC–Co and Ti(C, N)–19%WC–Co upon radial turning was measured as a function of the cutting speed. Ab initio calculations of some grain boundary geometries in WC–Co indicated that Co segregates to WC/WC grain boundaries in submonolayer proportions and increases their strength and resistance to Co infiltration. This was also confirmed with TEM-EDX. SEM studies showed that during plastic deformation the hard phase skeletons in both materials were partly broken up and infiltrated by binder phase. TEM observations showed a considerable deformation of the WC grains and some infiltrated grain boundaries were facetted along low energy planes. In the cermet, no deformation of the hard phase grains could be seen. The plastic deformation at high temperatures observed by three-point bending corresponds to a number of relaxation processes, detected by internal friction, related to grain boundary sliding. Both materials deform by grain boundary sliding, accommodated in the cermet by Co diffusion and in the WC–Co by deformation of the hard phase and diffusion of Co.

DFT

Plastic deformation

Cemented carbides

Internal friction

Characterisation

Author

Gustaf Östberg

Chalmers, Applied Physics, Microscopy and Microanalysis

Katharina Buss

Swiss Federal Institute of Technology in Lausanne (EPFL)

Mikael Christensen

Chalmers, Applied Physics, Materials and Surface Theory

Susanne Norgren

R and D Materials and Processes

Hans-Olof Andrén

Chalmers, Applied Physics, Microscopy and Microanalysis

Daniele Mari

Swiss Federal Institute of Technology in Lausanne (EPFL)

Göran Wahnström

Chalmers, Applied Physics, Materials and Surface Theory

Ingrid Reineck

R and D Materials and Processes

Int. J. Refract. Hard Mater.

0263-4368 (ISSN)

Vol. 24 1-2 135-144

Subject Categories

Condensed Matter Physics

DOI

10.1016/j.ijrmhm.2005.04.009

More information

Latest update

5/3/2018 1