Residual thermal stress, fracture toughness, and hardness in WC-Co cemented carbide: Finite element simulation and experimental verification

Abstract

The finite element method has been widely used in property simulations and the design of cemented carbides, but most of the simulations have focused on individual properties of the alloy, and few studies were done on multiple properties to explore the micromechanical properties simultaneously. In this work, a finite element model is established based on the real microstructure from scanning electron microscopy images of cemented carbide, and elastoplastic properties are imparted to both WC and Co phases. The residual thermal stress, fracture toughness, and hardness of WC-10 wt.%Co cemented carbide were subject to different external stresses. The average normal stresses of the WC and Co phases obtained by the residual thermal stress simulation are −170 and 920 MPa at 25 °C, respectively. The crack initiation and propagation due to the fracture toughness model tend to concentrate on the WC/WC boundary where the stress is concentrated. The alloy hardness (HV30) calculated from the load-displacement curve is 1850. These simulation results are in good agreement with the experimental results, which proves the feasibility of the models. The present work provides a simulation basis for further exploring the relationship between the microstructure and mechanical properties of cemented carbide and optimizing several mechanical properties simultaneously.

Keywords

• Cemented carbide
• Finite element simulation
• Residual thermal stress
• Hardness
• Fracture toughness