アルミニウム合金とエポキシ系接着剤の接着強度に対し，アルミニウム表面の腐食反応が及ぼす影響を評価した。電気化学的な分極試験によりアルミニウム合金とエポキシ接着剤の界面を加速劣化させたところ，アルミニウム表面の腐食挙動と接着強度特性との間に相関があることが分かった。また種々の分析手法を用いて接着界面の状態変化を分析した結果，接着接合部の強度低下は界面への水の侵入とそれに伴う腐食反応によって促進されることが示唆された。

With the increasing demand for weight reduction in the transportation industry, reliable joining technologies for thermoplastic resins, including CFRTP, to metallic materials have become increasingly important. This article reviews friction stir welding（FSW）of polymers to metals, focusing on interfacial bonding mechanisms and strengthening approaches. Unlike conventional FSW of metals, polymer–metal FSW does not require stirring of the metallic material. Joining is achieved using a probe-less tool, where frictional heat locally melts the thermoplastic resin at the interface, enabling bonding to the metal. At the interface, hydrogen bonding occurs between hydroxyl groups on the metal oxide layer and polar functional groups in the polymer. In addition, covalent bonding such as Al–O–C linkages has been reported, contributing to joint strength. Mechanical interlocking due to surface roughness also enhances bonding strength. Furthermore, silane coupling treatment promotes interfacial covalent bonding. High-strength and reliable joints can be achieved by combining these mechanisms based on localized melting. Polymer–metal FSW is therefore a promising method for dissimilar-material joining.

Hydrogen energy is widely recognized as a key technology for achieving a carbon-neutral society because it does not emit carbon dioxide during use. Hydrogen can be produced from water and, when utilized in combination with renewable energy sources such as solar and wind power, functions as a clean and sustainable energy carrier that helps reduce dependence on fossil fuels. Nevertheless, the practical implementation of hydrogen energy requires the development of safe, durable, and reliable hydrogen storage and handling technologies. Materials used in hydrogen-related systems must withstand harsh environments, including high pressure, cryogenic temperatures, and continuous exposure to hydrogen. This paper reports recent progress in materials development for hydrogen storage applications. In particular, we focus on liner materials for highpressure hydrogen tanks, which are critical for gas tightness and long-term durability, and valve materials for liquid hydrogen systems, which must maintain mechanical strength and sealing performance under extremely low-temperature conditions. These developments highlight the importance of advanced materials in establishing a reliable hydrogen energy infrastructure.

This article describes the effects of vacuum ultraviolet （VUV） light irradiation on the adhesive bonding strength of carbon fiber-reinforced polyphenylene sulfide （PPS）and carbon fiber-reinforced polyimide （PI） composites, which are highly anticipated for aerospace structural applications. Furthermore, bonding processes using PI adhesives and joining technologies utilizing highly heat-resistant thermoplastic polyimide（TPI）films are discussed. When bonding carbon fiber-reinforced PPS with an epoxy adhesive, the distance between the xenon excimer lamp and the specimen significantly influenced the bonding strength. Conversely, the irradiation time had a minimal impact, and it was found that excessive irradiation actually led to a decrease in strength. When joining carbon fiber-reinforced PI composites using a TPI film, the bonding strength obtained even without irradiation was comparable to that achieved with an epoxy adhesive. Moreover, VUV irradiation of the adherends significantly enhanced the adhesive strength. Although sufficient bonding strength may not always be achieved when joining heat-resistant composite materials with heat-resistant adhesives, VUV light irradiation has proven to be a highly effective surface treatment method for overcoming this challenge.