Effect of Severe Plastic Deformation on the Properties and Structural Developments of high purity Al and Al-Cu-Mg-Zr Aluminium Alloy

Abstract

Demands of industry producers are to find new forms and facilities for appropriate properties of structural parts suitable for different miscellaneous structural applications in the civil, automotive and aircraft industries. With respect to these facts, aluminium alloys find a wide variety of uses due to their remarkable combination of characteristics such as the low density, the high corrosion resistance, high strength, easy workability and high electrical and heat conductivity. The traditional process is to obtain the improvement in the mechanical properties of aluminium alloys through the precipitation of a finely dispersed second phase in the matrix. This is accomplished by a solution treatment of the material at a high temperature, followed by quenching. The second phase is then precipitated at room or elevated temperatures. For aluminium alloys this procedure is usually referred to as age hardening and it is also known as precipitation hardening (Michna et al., 2007); (Mondolfo, 1976). Conventional forming methods are ineffective in the achieving of favourable properties area of produced parts, adequate to structural properties; moreover through them only limited levels of structural and strength-plastic characteristics can be obtained. The solution may be non-conventional forming methods (Kvackaj et al., 2005), (Kvackaj et al., 2004), (Kvackaj et al., 2010 a) as well as Severe Plastic Deformation (SPD), such as more preferable are equal channel angular pressing ECAP, (Valiev & Langdon, 2006), (Valiev et al., 2000) to obtain results structured at the nm level. A combination of high strength and ductility of ultrafine polycrystalline metals, prepared by SPD, is unique and it indeed represents interesting cases from the point of view of mechanical properties (Chuvil’deev et al, 2008); (Zehetbauer et al., 2006); (Han et al., 2005) ;(Ovid'ko, 2005); (Meyers et al., 2006); (Kopylov & Chuvil’deev, 2006); (Zehetbauer & Estrin, 2009). In the past decade, the research focused on to strengthen Al alloys without any ageing treatment, via SPD (Kvackaj et al., 2010 b). The finite element method (FEM) is a proven and reliable technique for analyzing various forming processes (Kvackaj et al., 2007); (Kocisko et al., 2009); (Li et al., 2004); (Leo et al., 2007); (Cerri et al., 2009), (Figueiredo et al., 2006); (Mahallawy et al., 2010); (Yoon & Kim, 2008), in order to analyze the global and local deformation response of the workpiece with