Processing of aluminium alloys by equal channel angular pressing - ECAP

Abstract

Aluminium alloys have been the main material used in aeronautic sector that claims for continuous development with the aim to reach better and optimised properties as low density, high strength without ductility loss, high fatigue and stress corrosion cracking resistance. Due the recent development of sub-micrometers or nanometers materials, it has been possible to reach this aim. Among the different methods of obtainment of refined microstructure, severe plastic deformation, especially equal channel angular pressing - ECAP, presents several advantages by overcoming of a number of difficulties as residual porosity and impurities, and make possible processing of large scale billets and industrial application of the given materials. Although a lot of researches have been done about ECAP method on processing of aluminium alloys and its effects on properties, there is still so much to be done. In this way the aim of this project is to study the processing of commercial aluminium alloys by ECAP, evaluating the effect of processing conditions and of the initial microstructure on the development of microstructure during pressing (grain refining, precipitation, fragmentation or dissolution of precipitates, defects structure) and the effects on mechanical properties. (AU)