FRACTURE OF AN OSPREY(TM) ALSIFE ALLOY - A MICROSTRUCTURE BASED MODELFOR FRACTURE OF MICROHETEROGENEOUS MATERIALS

This paper is concerned with the failure in tension of an AlSiFe alloy with a particular composite type microstructure. The experimental obs ervations allow to distinguish three main steps in the damage process: nucleation by the cracking of some big silicon particles, increasing of the number of cracked particles with macroscopic plastic strain and final failure by joining of the microcracks thus created. This schema tizaton is the basis of the modelization which requires Eshelby type c alculations and energetic balances. This model is in good agreement wi th experiment for the studied alloy and makes the microstructural para meters of the material dearly appear.