Microstructure-Level Model for the Prediction of Tool Failure in WC-Co Cutting Tool Materials

Abstract

A model to predict tool failure due to chipping in machining via the microstructure-level finite element cutting process simulation is presented and applied to a wide variety of WC-Co tool materials. The methodology includes the creation of arbitrary microstructures comprised of WC and Co phases to simulate various grades of WC-Co alloys. Equivalent stress, strain, and strain energy are then obtained via orthogonal microstructure-level finite element machining simulations. A model was developed to predict the occurrence of tool failure based on the mixed mode fracture criterion. Turning experiments were conducted to validate the model and the results showed that the model predictions agree well with the observations from the experiments. The model was then employed to study the effects of microstructural parameters and feedrate on chipping and failure.