Finite Element Modelling of Functionally Graded Cemented Tungsten Carbide Compaction with Flow Stress Estimation

Abstract

Preparation of functionally graded material (FGM) is a challenging task for researchers in regard to the development of effective gradient having tuneable properties such as density, hardness, strength, etc. Although a number of the methods are available but powder metallurgy (PM) is an effective amongst them for creating defect free gradient. In the present work, PM route is adopted for the preparation of WC-Co FGM where strength is directly correlated with density. The prepared FGM performance is significantly influenced by the different parameters such as the size of powder particles, compaction pressure, punch speed and method of compaction, therefore compaction process is crucial for the prepared FGM quality. Punch speed, a method of compaction (single action and double action compaction) are considered as variables for simulation. The finite element method is implemented for simulation of compaction to know the deformation nature of powder. This deformation nature is helpful for prediction of final compact density. Flow stress is the major input parameter to model deformation behaviour of material and is estimated by “Johnson-Cook model”. The predicted results are in well accord with the work done by Favrot et al. It is observed that with an increasing punch speed density increases simultaneously. In addition to this under same experimentation condition, double action compaction produces more density compare to single action compaction. These results will be helpful to assess the influence of punch speed and compaction method on the density of compacted powder for the research community.