Unidirectional solidified Al–Fe hypereutectic alloy wires 6 mm in diameter have been produced by the Ohno Continuous Casting (OCC) Process at casting speeds of 0.83–8.3 mm/s. The effects of casting speeds on cast structure and crystal orientation of the wires have been studied. The cooling rate of cast wires were increasing in proportionality relation with increasing casting speeds. At lower casting speed, the cast structure consisted of unidirectional solidified eutectic cell. However, at casting speeds above 3.3 mm/s, this inter-metallic primary phase was no longer observed, but instead α-aluminum dendrites (primary crystals of hypoeutectic compositions) were present as the primary phase. It was also found that at lower casting speeds, the crystal orientation of cast wires in the casting direction tended to be 〈111〉, while at casting speeds above 3.3 mm/s, the crystal orientation tended to be 〈101〉 and the cast structure contained Σ3 coincidence boundaries.

A2024 aluminum alloy studs were joined to aluminum alloy/resin composite panels by solid-state stud welding method. The studs have a circular projection at its bottom. Five different shapes of the projections were prepared in this study. Effects of joining conditions and projection shapes on the interfacial morphology and tensile fracture load of joints were evaluated. Heating effect on the adhesive layer between skin and core plate of the composite panels was also investigated. In the basic projection shape used in the conventional solid-state stud welding method, it was impossible to join to the composite panels. However, joining was achieved by improving the projection shape. The interfacial morphology and tensile fracture load of the joints were different, depending on the difference in the projection shape. The strong joint could be realized by the appropriate joining conditions. If the charged voltage is too large, there is a possibility that the thermal influence during joining will extend to the adhesive layer, and the adhesive strength between skin and core plate will be reduced. Therefore, it is necessary to provide a projection shape sufficiently plastic deformed inside the skin of the composite panels even at lower charged voltage in order to obtain sound joints.

The plate bending fatigue tests were conducted under two conditions of stress ratio of 0 and −1, to investigate the effect of microstructure on the fatigue properties of Mg–6 mass%Al–1 mass%Zn–1 mass%Ca rolled plates along the rolling direction (RD-specimen) and the transverse direction (TD-specimen). Fatigue limit of the RD-specimen was almost the same as that of the TD-specimen when the stress ratio was −1. On the other hand, fatigue limit of the RD-specimen was slightly higher than that of the TD-specimen when the stress ratio was 0. SEM observations indicated that fatigue cracks initiated from the surface stressed in tension, and the second phase particles (Al–Ca compounds) acted as the crack initiation sites. Crack propagation direction was perpendicular to the stress direction, and the fracture occurred as a result of the crack connection. The crack length was larger in the TD-specimen than the RD-specimen especially for the case under the stress ratio of 0, and hence the anisotropy of the fatigue properties was apparently in the TD-specimen as compared to the RD-specimen. Although deformation twins were formed near the surface during the fatigue tests, they were not likely the governing factor of the crack initiation.