A.Densification and Flow Stress Evolution Constituative Model for Powder Based Discontinuously Reinforced Aluminum Materials

摘要

Discontinuously Reinforced Aluminum (DRA)composites are a class of material that has generated muchinterest in the automotive industry due to its combination ofoutstanding mechanical properties and lighter weight with respectto steel. The relatively high processing costs of DRA materialhowever, has restricted its widespread use in many automotiveapplications. The development of a densification and flow stressevolution constitutive model for DRA composite materials ispresented. A porous yield criterion based on the Gursonmicromechanical model, as modified by Tvergaard, Richmondand Smelser, and Wang is used to predict the densificationresponse of the powder processed composite material. Theevolution of flow stress during axisymmetric compression testinghas been modeled using the hyperbolic sine law and singleinternal state variable theory. The material constitutive model canthen be imbedded in standard FEM codes to allow realisticdeformation processing simulations of actual automotivecomponent geometries produced from DRA composite material.