The Effects of Mechanical Vibration, Grain Refinement and Modification on the Structure and Mechanical Properties of A380 Aluminum Alloy

This research concentrates on the effects of low frequency, vertical mechanical vibration during solidification on the microstructure and mechanical properties of A380 aluminum alloy. Two series of Sr-modified and Al-5Ti-B grain refined A380 alloy samples were solidified in both static and dynamic conditions in the frequency and amplitude of 60 Hz and 0.2 m, respectively. Their Physical, micro-structural and mechanical properties such as ?UTS, ?Y, elongation, hardness, density and SDAS were compared to those of sample solidified in the dynamic condition without any additives. The results indicated that the gas and shrinkage porosities were reduced by vibration through intensifying mass feeding. As a result, density and hardness increased with applying vibrational energy. Vibration decreased SDAS and refined eutectic silicon in unmodified condition and caused coarsening of eutectic silicon in Sr-modified samples. Mechanical parameters such as ?UTS, ?Y, elongation and quality indices were increased in dynamically solidified samples. Vibration influenced elongation more than tensile strength.