The environment surrounding automotive has changed dramatically, and we are entering a period of
revolution once in 100 years. In these trends, the necessity of CFRP including CFRTP and their issues are
discussed with its bonding technology, especially focusing on adhesives.
As a result of discussion in this review, CFRP is expected to be very useful, because not only for the weight
reduction leading to the reduction of CO2 emission through vehicle driving, but also leading to a significant
reduction in the number of component parts of the vehicle. Full-scale LCA measures are extremely important
in terms of total energy consumption of the material productions and assembly.
There are still many problems about its bonding technology, because spot welding method, like on steel
plates, cannot be adopted. On the other hand, usages of adhesives and unique methods like CFRTP fusion
method are being considered.
In addition to the test piece level evaluation, bonding methods in actual parts require measures to ensure
long-term reliability. Especially, in the case of boding different kinds of materials, the thermal stress and electrolytic
corrosion are both very important to be considered.
In the future, if we could discuss adhesives not only on the structural aspects, but also on the functional aspect,
it is possible that new developments will be seen with extreme interests.
Adhesive joining is currently being focused on as a key joining technology for industrial application like
architecture, aircraft and automotive, because it provides fruitful benefits for joint design such as dissimilar
material joining, crash energy adsorption improvement, and protection from galvanic corrosion. In the case of
adhesion of metals, however, its adhesion strength and stability strongly depend on metal surface condition,
like oxide layer thickness, chemical state or adsorbate; and they often cause problems or failure of adhesion.
This review briefly summarizes a series of studies of adhesive joining technology of metals in several topics;
merit of adhesive application for joining, surface condition and preparation method of metals for adhesion,
analytical method and knowledge of metal surface and adhesion interface.
This article reviews the recent development of the test method for the evaluation of toughness and
durability of the interfaces in dissimilar adhesive joints. The test specimens of carbon-fiber-reinforced
thermoplastic( CFRTP) with polyamide-6( PA6) matrix and Al alloy were bonded with epoxy and urethan
structural adhesives. Double cantilever beam( DCB) test was employed for the determination of the interfacial
toughness, while the wedge test was performed for the evaluation of durability under a high-humidity and
high-temperature condition. The crack growth along the interface in DCB test was monitored with the
assistance of the mechanoluminescence( ML) for the accurate detection of the phenomena at the crack tip. It
was found that the adhesive joints were failed by various failure modes depending on the surface pretreatment
and environmental conditions. Throughout the work, discussion was made concerned with the interfacial
structures and the adhesion mechanism of the dissimilar adhesive joints.
Structural adhesive joining is a key technology for weight reduction of a carʼs body as a means of CO2
emission reduction. The biggest issue of the structural adhesive joining is to maintain quality and function
throughout the productʼs lifetime in various markets.
In this paper, firstly we revised a background, trends and current issues of the technology in automotive
industry, then introduced two rheological examples of Mazdaʼs latest approaches to damping for comfortable
driving and to adhesive-defect studies.
近年のマルチマテリアル構造の普及に伴い,接着接合への期待が高まっている。また,これに対応可能
な接着剤も登場している。この場合,異種材料の接合が最も重要となるが,接着剤はこの特性を最初から
有しており,そもそも問題は少ない。熱応力やガルバニックス腐食などの問題は残るが,これにも対処は可
能である。今後は材料リサイクルの観点で解体性が,車体の品位向上のために制振性が求められるであろう。
異種材料を適材適所に配置し,軽量化とコストの最適化を図るマルチマテリアル構造が注目されている。
これは自動車車体のみならず,航空機や船舶など,どの移動体でも生じているトレンドであり,省エネル
ギーの観点で極めて重要である。一方,たとえば自動車と航空機では,材料選択の根拠がかなり異なるため,
マルチマテリアル構造といってもかなり異なった形となる。また,異種材料の接合が必須となるため,接
着接合が使用される場合が多い。