The effects of forging temperature on the distribution of Al₃Ti platelet particles in Al–Al₃Ti multi-phase materials deformed by multi-directional forging (MDF) are investigated. The Al–Al₃Ti multi-phase materials consist of large Al₃Ti platelet particles and α-Al matrix. The MDF is performed at either room temperature (RT) or 573 K, and the Al₃Ti platelet particles are refined at both temperatures. The refined particles in the specimen subjected to MDF at 573 K are larger than those in the specimen subjected to MDF at RT. This size difference can be explained by dynamic recrystallization of the α-Al matrix during MDF. Furthermore, the change in the spatial distribution of the refined Al₃Ti particles in the forged specimens is evaluated using Morishita’s index. Based on the results, it is found that the spatial distribution of the particles changes depending on the plastic flow of the α-Al matrix during MDF. In addition, the change in spatial distribution of the particles is greater when MDF is carried out at RT than at 573 K. Therefore, it is concluded that the size and spatial distributions of the Al₃Ti platelet particles in the Al–Al₃Ti multi-phase materials deformed by the MDF depend on the forging temperature.

A Ti–6Al–7Nb alloy was processed by severe plastic deformation through high-pressure sliding (HPS) at room temperature for grain refinement. The microstructure consists of grains with sizes of 100–200 nm in diameter having high and low angles boundaries. Superplasticity appeared with the total elongation of more than 400% and this was more likely when the tensile specimen is deformed in the direction parallel than perpendicular to the sliding direction. However, the superplastic elongation is almost the same irrespective of whether the sliding was made in the single direction or in the reversible directions as far as the total sliding distance is the same. The total elongation is invariably higher for the tensile testing at 1123 K than at the other temperatures, reaching the highest elongation of 790% at the initial strain rate of 1×10⁻³ s⁻¹. The strain rate sensitivity and the activation energy for the deformation were determined to be more than ～0.3 and 200 kJ/mol, respectively. The microstructural observation reveals that the α phase region covers more than 85% of the tensile specimens after deformation and their grains are equiaxed in shape. It is concluded that the superplastic deformation is mainly controlled by grain boundary sliding through thermally activation by lattice diffusion.

Corrosion mechanism and morphology changes of aluminum alloy in model solution corresponding sea water containing gluconates and zinc ions were investigated by immersion corrosion tests with surface analysis. Surface and cross-sectional SEM results showed that zinc ions suppress the morphology changes of aluminum alloy in the solution containing gluconates. XPS analyses indicated that gluconates in the solutions adsorb on the oxide films of aluminum alloy and protective films of the adsorbed gluconates would prevent the penetration of chloride ions to the aluminum alloy. The XPS results also suggest that zinc ions in the solutions bond to the oxide film of aluminum alloy and zinc ions enhance the corrosion inhibition ability of the protective films of gluconates for aluminum alloy in model sea water.