Numerical simulation of fatigue crack propagation in WC-Co hardmetal

Abstract

WC-Co cemented carbides (hardmetals) are a group of composite materials exhibiting outstanding
combinations of hardness and toughness. As a consequence, they are extensively used for highly
demanding applications, such as cutting and drilling tools, where cyclic loading is one of the most
critical service conditions.
A numerical study of the mesoscale fatigue crack growth in WC-Co is here conducted. Within this
context, a model based on a continuum damage mechanics approach was implemented in
commercial solver Abaqus/Explicit for simulating the crack propagation in the material. Separate
damage laws, based on brittle failure and fatigue, were used for describing the mechanical
response of WC and Co phases, respectively. Material parameters for the carbide phase were
taken from literature, whereas those for the metallic phase were experimentally determined in a
model binder-like Co-base alloy, i.e. one with a composition representative of the binder phase
within a commercial hardmetal grade.
In order to validate the approach used, a numerical model based on a real damaged microstructure
was generated. It is found that proposed model is capable of capturing damage evolution with
cyclic loading in WC-Co, as numerical results reflect satisfactory agreement with real crack pattern
resulting from experiments.