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.

The use of multi-material structures has recently been expanding much, and the hope for adhesive bonding

is rising. Various types of new adhesive were developed to meet the demand.　For this purpose, dissimilar

material joining is indispensable. Adhesives have these characteristics by nature. Thermal stress and Galvanic

corrosion are still problems, but they can be overcome. Additional characteristics, such as dismantlability for

recycling, damping for vibration of automobile will be required.

The use of multi-material structures, in which various materials were utilized at the proper positions, has

been expanding not only for cars but also aircraft and ships. This trend is quite common for every type of

transportation and very important in terms of energy saving. On the other hand, even using the same words,

the meaning of multi-material structures for automotive is quite different from those for aircraft because of

material selection. In addition, adhesive bonding is indispensable for the fabrication.