Thermodynamic and kinetic modeling for multicomponent cemented carbides and their applicationsThursday (29.09.2016) 10:00 - 10:15 Part of:
Cemented carbides usually consist of hard micrometer-sized carbides embedded in a metal binder phase. They play key roles in the production of hard and tough tool materials, which are used in high wear environments, such as cutting, machining and mining applications. In order to develop the new type of cemented carbides efficiently, the thermodynamic and kinetic modeling for the W–C–Co–Fe–Ni–Cr–Ta–Ti–Nb–V–Zr cemented carbides were established through a combination of assessment and experimental work. The thermodynamic modeling is based on critical evaluations of binary, ternary and even higher order systems which enable making predictions for multicomponent systems and alloys of industrial importance. The kinetic modeling contains the atomic mobility parameters for different diffusing elements in liquid and fcc phase. The Sutherland equation is modified in the present work to predict both self- and impurity diffusivities in liquid. The atomic mobility parameters in fcc phase are optimized by the diffusivities measured by experiment and from literature.
The developed multicomponent thermodynamic and kinetic modeling can be used to calculate the multicomponent phase equilibria, obtain the thermodynamic information and simulate the sintering process under different technological parameters. In order to validate the accuracy of currently established databases and show some industry-related applications, the cemented carbides are designed and prepared. Scanning electron microscopy (SEM) and electron back scattered diffraction (EBSD) are employed to investigate the microstructure of the cemented carbides, and electron probe microanalysis (EPMA) is used to determine the concentration distribution of the elements. The simulation results are compared with the experimental results to demonstrate the application of the established thermodynamic and kinetic modeling.