Mechanical characterization of powder materials: A general approach detailed for cemented carbides

Abstract

Material parameter curves in an advanced material model describing compaction of spray dried cemented carbide powder are determined successfully based on a general approach for material characterization of powder materials. Pressing forces from a production machine and equivalent finite element (FE) calculations are used in inverse modelling. A pressing method that includes multiple unloading steps is used. The material model is of Drucker Prager CAP kind and friction between powder and pressing tool is modelled as a function of normal pressure. The results are verified with density gradient measurements using a neutron source. The method is proven to be robust and the results show good agreement between experiment and simulation. Effects that have not been captured numerically previously are captured due to the high accuracy of material characterization. The present approach is detailed for tungsten carbide powders but is valid for other powder materials when properly calibrated for constitutive and frictional effects in the same manner as outlined here.