In this study, the effects of the nanoporous structure of anodic films on adhesive strength between aluminum alloys and polyamide resin were systematically investigated. To compare the anchoring effect, the alumina films with different dimensions (e.g., pore density, pore diameter and pore depth) were formed on A6063 aluminum alloys by various anodizing conditions. The adhesive strength at the interface between the adherent (anodized aluminum) and adhesive (thermoplastic elastomer resin) was evaluated by a method for determining the tensile lap-shear strength of rigid-to-rigid bonded assemblies. The higher pore density and larger pores in anodic films were important factors for improving the adhesive strength and increasing the adhesion interface area and the amount of adhesive impregnated into the pores. The adhesive strength of aluminum after anodizing in phosphoric acid at 60 V and subsequent pore widening was 17.4 MPa, which was ～3.5 times higher than that of an aluminum substrate without surface treatment.

Effects of anodization by using a phosphate solution and via laser irradiation on the adhesive properties of an AZ91D magnesium alloy were evaluated to produce multi-materials for the purpose of fabrication of the lightening materials. AZ91D sheets were anodized, and then post-treatment was carried out by dipping the sheets in nitric acid solution to improve the adhesive property. The anodized film suppressed the reflection of laser beam and improves laser workability. It was possible to obtain a joining strength of more than 10 MPa by drilling the AZ91D sheets treated with anodization by optimal laser irradiation. Furthermore, the anodization in phosphate solution modifies the surface of the magnesium alloy to an inactive state, thus suppressing the deterioration of adhesiveness due to oxidation that occurs in the untreated material.

The shaping of porous aluminum (Al) is indispensable for its wide use in various industrial fields. In this study, the cutting of porous Al was attempted right after a precursor was foamed. The precursor was heated by optical heating to fabricate porous Al, and then the porous Al was cut by passing a cutter through it. From the surface temperature of the porous Al immediately before the cutting process and the observation of pore structures in the cross section after cutting, it was found that the cutting surface was good when the temperature was lower than the liquidus temperature of the base material. On the other hand, when the cutting temperature was low, the porous Al collapsed and could not be cut. X-ray computed tomography (CT) observations of the cut porous Al showed that the cutting did not affect the inner pore structures of the porous Al. This suggests that cutting while maintaining the pores of porous Al is possible.

Stress-strain relationships of A5052-O subjected to various cross loading paths were experimentally observed. Cross-loading paths consist of the uniaxial tension in the rolling direction and the following simple shear applied along the orientation inclined at 0°, 45°, 90°, and 135° from the rolling direction. These cross-loading paths result in so-called orthogonal, quasi-monotonic, and quasi-reverse loadings. In the orthogonal loading, the reyield stress and the subsequent flow stress were higher than the flow stress in the monotonic simple shear, and the work hardening rate was decreased. The same type of the work hardening behavior was observed even for the quasi-reverse and quasi-monotonic loadings. Thus, cross effect occurred for a wide range of the change in the strain paths. Subsequently, the cross-loading paths were applied to a steel sheet (SPCE). For the steel sheet, the reyield stress was reduced in the quasi-reverse loading, and no cross effect was observed for the quasi-monotonic loading. From comparisons of the cross-hardening behaviors and R values of A5052-O and SPCE, it is revealed that the tension-shear type cross loading cannot mimic the reverse and monotonic loading paths, if the R value is small.