IMPROVEMENT OF THE FRACTURE TOUGHNESS OF AN ALUMINIUM ALLOY

Abstract— The improvement of a material's toughness has significant industrial applications. An example is the manufacture and maintenance of commercial gas containers made in the form of aluminium cylinders; a challenging design problem since they are susceptible to crack growth under a static load (internal pressure). In this investigation a new thermo-mechanical technique was used to improve the apparent fracture toughness. This could increase significantly the safety margin and life of the cylinders. The determination of fracture toughness was carried out using a newly developed small cylindrical specimen which has a considerable cost advantage over the standard compact tension specimen. Experiments on aluminium 6351-T6 cylindrical specimens confirmed the possibility of improving the toughness of this alloy.