Papers by Keyword: Wrought Aluminium Alloys

Abstract: Friction Stir Processing (FSP) of various aluminium alloys including wrought 6061 and cast A356, 319, and A390 have been systematically investigated in this study. The effects of processing on microstructure, hardness, tensile properties, and fatigue crack growth behaviour of the alloys were studied. The alloys were judiciously selected to understand the effects of Si level, type, and morphology, and to evaluate the contributions of different secondary phases and strengthening precipitates. Individual and combined effects of these microstructural features were also assessed. The results will be presented and discussed.

Abstract: Regardless of whether it is cast microstructure, the grain structure that is the product of thermomechanical processing or the nanoscale dispersions of strengthening second-phase particles, it is inescapable that the structural scale that controls mechanical properties in Al alloys is determined primarily by processes of nucleation during either solidification, recrystallisation or solid-state phase transformation. In those advanced alloys with bulk amorphous or nanocrystalline structure, production of an amorphous precursor is reliant on initial suppression of the nucleation of crystallisation, and subsequent controlled nucleation of dispersed nanocrystals within amorphous matrix. The processes of nucleation that control structural scale in modern Al alloys are briefly reviewed, with a focus on potential for further structural refinement and advances in properties.