In this study, an attempt was made to braze porous Al samples fabricated by powder metallurgy with an Al–2.5 mass%Si alloy brazing sheet at 863–883 K. These porous Al samples were fabricated by using 99.9% purity Al powder. During the brazing process, the porous Al was deformed. The deformation was greater at higher brazing temperatures, and which resulted in reduced porosity localized at near the interface between the porous Al and the brazing sheet. As determined by cross-sectional observation after brazing, the cell walls of the porous Al showed a different microstructure compared to that prior to brazing. Electron probe microanalysis revealed the presence of Si in the cell walls after brazing. These results indicate that the liquid phase, which was formed in the brazing sheet during brazing and contained Si, migrated to the cell walls. To clarify the migration behavior of the liquid phase on the surface and in the cell wall, a sintered bulk Al sample was brazed with an Al–2.5 mass%Si brazing sheet at 873 K. The results suggest that the liquid phase preferentially migrated both on the surface and through the powder boundaries.

Mg–1.5Zr alloy blanks 1.0 mm in thickness, made from cast and rolled materials, were deep-drawn at room temperature and 150°C. The microstructures were examined and deformability evaluated. The grain size of blanks from cast and rolled materials was 40 µm and 15 µm, respectively. The basal texture was confirmed for rolled-blanks, while the microstructures of cast blanks were randomly orientated. The limiting drawing ratio for cast materials was 1.65 at room temperature and 1.75 at 150°C. For rolled-blanks, it was 1.45 and 1.70 at room temperature and 150°C, respectively. The cast-blanks deformed in a similar way at room temperature and at 150°C, exhibiting a decrease in thickness in the punch-shoulder areas and a progressive increase along the side wall toward the rim of the cups. Rolled-blanks tested at 150°C showed the similar trend as cast-blanks and exhibited evidence of dynamic recrystallization in the punch-shoulder areas, contributing to an improvement on the limiting drawing ratio. When the deep-drawing exceeded the limiting drawing ratio, the cast-blanks tested at room temperature and 150°C and also the rolled-banks tested at 150°C fractured in the rim area of the cups, while the rolled-blanks at room temperature fractured from the punch-shoulder areas.

Aluminum foam has the high-energy-absorption property together with its superior lightweight. However, the tensile strength and bending strength of aluminum foam is lower than those of dense aluminum materials. It is promised that a sandwich structure consisting of an aluminum foam core and dense metallic face sheets is used as a structural component. In this study, at first, we fabricated sandwich-type foamable precursors of ADC12 aluminum alloy with two A1050 aluminum face sheets using the friction stir welding route. Next, 3-point bending tests of sandwich-type foamable precursors were carried out and sandwich-type foamable precursors with curvature were fabricated. After that, it was shown that, by foaming these precursors, aluminum foam core sandwiches with the aluminum foam core of good pore structures and almost same curvature as those of sandwich-type foamable precursors were successfully fabricated.

The fracture occurring at the flange edge in the process of cylindrical deep drawing of AZ31B magnesium alloy sheets was investigated. The fractures were simulated under a uniaxial in-plane compression test to classify the fracture types while the blankholder force of the sheet was varied. Two types of fractures, out-of-plane shear fracture (OPSF), and in-plane shear fracture (IPSF), were observed. The fracture types changed from OPSF to IPSF as the blankholder force increased to a drawing ratio of approximately 1.5–1.6. This implies that the fracture type could be controlled by changing the blankholder force. The transition from OPSF to IPSF increased the fracture strain, because the out of plane buckling of the alloy sheets was suppressed by the blankholder force. The results confirmed that, in cylindrical deep drawing, the limiting drawing ratio could be increased by restraining the flange edge of the alloy sheets with the sufficient blankholder force.

It is known that roll coating is formed on work rolls in cold rolling of stainless steel, copper alloys or aluminum alloys. It affects surface properties of rolled strip, rolling characteristics and amount of wear debris formed. By the way, actual rolling mills have back-up rolls, which are equipped in order to reduce the deflection of the work rolls. In this study, cold rolling of Al–Mg alloy A5182 is conducted in laboratory to investigate the effects of back-up rolls, on the rolling lubrication with a pair of back-up rolls which have groove at the center of the barrel. The backup roll does not contact with the roll coating on work roll when using the grooved backup-roll. As a result, it is found that the attainable maximum reduction in thickness is reduced by approximately 10 point compared with the case using normal flat back-up rolls. In addition, cold rolling of aluminum A1050 is conducted to investigate the effects of back-up rolls, on amount of wear debris formed in rolling lubricant. As a result, it is found that in the case of normal flat back-up rolls, the amount of wear debris is pronounced than the case of grooved back-up rolls.

Mg–Ce alloy single crystals with different quantities of cerium were subjected to [1̄100] and [112̄0] tensile tests so as to clarify effects of cerium addition on activation of non-basal slips at room temperature. Mg–0.016 mol%Ce alloys yielded due to {101̄1} twins in [1̄100] tension tests. Mg–0.052 mol%Ce single crystals yielded due to {112̄2}〈1̄1̄23〉 second order pyramidal 〈c+a〉 slip (SPCS), similar to pure magnesium single crystals, in [112̄0] tensile tests. Cerium addition decreased critical resolved shear stresses (CRSS) for {101̄1} twinning and SPCS. The decrease in CRSS for SPCS likely results from that the frequency of sessile (c+a) dislocations decreased with decreasing stacking fault energy of second order pyramidal planes.

Pure Mg, Mg–0.016 mol%Ce alloy and Mg–0.028 mol%Ce alloy single crystalline thin sheets were subjected to plain bending fatigue tests so as to clarify effects of cerium addition on fatigue fracture behavior of magnesium. Fatigue limit and fatigue life improved by cerium addition. With increasing cerium concentration, fatigue crack initiation lives became short, while crack propagation rates decreased. Critical resolved shear stress for second order pyramidal slip decreased by cerium addition, resulting in short fatigue crack initiation lives.