Equal channel angular pressing of an Al-4% Cu alloy in two initial conditions: as-cast and extruded conditions

Abstract

Equal channel angular pressing (ECAP) is the name given to a deformation process able to produce very fine grain size in metallic alloys. Its central characteristic is the ability to produce severe plastic deformation, thus providing a very high thermodynamic potential for processes such as recovery and recrystallization. Deformation levels are very high, reaching 15 or more, and can be obtained under relatively low mechanical loads and in conventional presses. Current research is mainly directed to process features: die geometry, processing routes, post-deformation heat treatments and microstructural changes due to the deformation. These studies deal with fundamental aspects of plastic deformation, ultra-fine grains formation mechanisms and how to reach high levels of mechanical strength and ductility. This IC project is part of a global project which seeks the application of ECAP-deformation to an Al-4%Cu alloy using three different initial conditions. In this case, ECAP will be applied at room temperature to an extruded, homogenized and slow cooled Al-4%Cu alloy. Results will be compared with as-cast and homogenized conditions, previously known. Characterization includes hardness measurements, tensile tests and fractografic analyses. The main aim is to evaluate the ability of ECAP process to "close" defects, as pores and solidification voids, and the importance of that mechanism front the tensile properties of the material.