In this study, electromagnetic stirring (EMS) was applied to the 7150 aluminum alloy during the solidification process to refine the microstructure of rectangular sectional sample. EMS was applied as clockwise and counterclockwise alternatively with reverse imposition time T. Then the effects of T and the cross-sectional dimension of the sample, that is the aspect ratio AR and corner radius R were evaluated. The average grain size at the center part was smallest at T=1 s and increased with increasing T. The grain size at the corner had the same tendency at the round type mold, the corner radius of which is half of the mold thickness. But it was smallest at T=2 s at non-round type mold. In the rectangular sectional sample with small R, the flow was not reached enough to the corner at T=1 s. But in T=2 s, the flow was reached to the corner because the flow became disturbed. In the round type mold, the flow was also reached to the corner even in T=1 s. This is considered to be a reason for the difference in tendency of grain size at the corner. Moreover, even in AR=5, the microstructure could be refined by applying EMS.

The effects of temperature and strain rate during hot rolling on the microstructure and tensile properties of high-strength Al–Zn–Mg–Cu alloy were investigated. Hot rolling was performed with controlled temperature (300°C, 350°C, 400°C) and strain rate (0.3/s, 2.0/s). Hot-rolled samples were prepared by solution heat treatment followed by T6 aging treatment. With the increase of the Z parameter calculated from the temperature and strain rate during hot rolling, the 0.2% proof stress after T6 treatment increased by up to 20 MPa at the surface region of the rolled sheets and by up to 8 MPa at the center region. This is because the average subgrain diameter became smaller as the Z parameter increased. In addition, the 0.2% proof stress of the center region of the rolled sheets was about 70 MPa higher than that of the surface region. At the center region, the orientation densities of Brass texture ({011}〈211〉), S texture ({123}〈634〉), and Cu texture ({112}〈111〉) were higher than that of the surface region. Therefore, the Taylor factor was higher at the center region than the surface region, and as a result, the 0.2% proof stress of the center region became high.

To form Al–Mn–Zn ternary alloy film, electroplating experiments were carried out in low temperature AlCl₃–NaCl–KCl molten salt at 423 K. In voltammogram measurement, Mn ions were reduced with Al ions at lower than −0.08 V vs. Al/Al(III) in AlCl₃–NaCl–KCl melt containing MnCl₂. Zn ions reduction started at 0.2 V in the melt containing ZnCl₂ and the reduction current increased with increasing ZnCl₂ concentration. Compositions of Al–Mn–Zn alloy were changed by ZnCl₂ concentration and electrolysis potential. A relatevely glossy surface was formed in 91at%Al–8at%Mn–1at%Zn alloy and a dull surface was formed in 90at%Al–8at%Mn–2at%Zn alloy. In XRD measurement, intensity of amorphous phase decreased with increasing Zn concentration in the alloys.

Effects of alloy compositions and concentrations on ignition temperatures of various Mg alloys with different shapes (foil and powder) were investigated by using differential thermal analysis. Foils of Mg–3 mass%Al–1 mass%Zn–1 mass%Ca (AZX311) and Mg–5%Y–4%RE (WE54) alloys exhibited almost the same ignition temperature, and those exhibited higher ignition temperature than Mg–3%Al–1%Zn alloy. On the other hand, powder of WE54 exhibited higher ignition temperature than that of AZX311, indicating that ignition temperature had strong relationship with solidus temperature of the alloy, when specific surface became large. Next, effects of Ca, Al and Zn concentrations on ignition temperature of the alloys were investigated. Increase of Ca concentration (more than 0.2%) contributed to significant increase in ignition temperature in the case of foils. On the other hand, powders exhibited less dependence of Ca concentration on ignition temperature. TEM-EDS observation revealed that Ca addition to Mg–Al alloy contributed to thinning of oxide films, and densification of the oxide films accompanied by thinning was likely attributed to an increase in ignition temperature. Effects of Al and Zn concentrations on ignition temperature exhibited qualitatively the same tendency between those of Ca concentration. However, contribution of Al and Zn concentration was much smaller than that of Ca concentration.