Real microstructure-based simulation of thermal residual stresses in cemented carbides and the related strengthening and toughening consideration

Realistic representation of the stress and its distribution in a composite material requires the use of a model based on the real microstructure. In this work, an image processing technique for transferring scanning electron microscope image into a finite element (FE) model is introduced in detail. Based on the aforementioned FE model, thermal residual stresses (stresses for short) in the hard and binder phases in a WC-Co alloy are assessed and presented mainly in a form of distribution contour. The parameters include the average stresses and their evolution with temperature, the mean stress frequency distribution of each element in the FE model, the maximum and the minimum principal stress distributions and the corresponding stress directions, as well as the Von Mises stress distributions. Based on the results concerning the existing positions of the innate microstructure defects, the strengthening and toughening mechanism of cemented carbides and the Martensitic transformation mechanism of the Co based binder phase are discussed.