Geometry effects during sintering of graded cemented carbides: Modelling of microstructural evolution and mechanical properties

Abstract

Cemented carbides with mesoscopically non-homogeneous properties by design represent a potential to enhance performance in metal cutting and rock drilling. Development of in-homogeneous structured hard materials through an ICME approach requires a thorough understanding of diffusion kinetics during solid and liquid state sintering. In this work, we used thermodynamics and diffusion kinetics modelling tools to predict the microstructure and resulting properties of cemented carbide composites. First, we designed and gradient sintered two (WC-TiCN-Co) cemented carbides with different nitrogen to titanium ratios. Second, we reproduced the experimental results in 2D by means of thermodynamic and kinetic simulations. In the last step we calculated fracture toughness KIC, and Vickers hardness of cemented carbides. The agreement between simulations and experimental results is fair and acceptable.

Keywords

• ICME
• Diffusion
• Cemented carbides
• Gradient sintering
• Hardness
• Fracture toughness