Correlation Study Between the New JASO M 609 Method and Accelerated Evaluation Method for Corrosion Resistance

Tatsuya Ezaki･Teruaki Asada (Mazda)

For the development of high-quality rust prevention in automobiles, a highly accurate and efficient method for evaluating the corrosion resistance of coatings is crucial. Recently, the new JASO M 609 method has been established as a corrosion testing method with higher market correlation. The accelerated evaluation technology developed to efficiently assess corrosion resistance also correlates highly with this new JASO method and is effective for developing high-quality rust prevention in a wide range of applications.

Analysis of the Relationship Between Solvent Diffusion Behavior and Polymer Chain Relaxation in the Chemical Resistance of Automotive Interior Decorative Films

Takito Shibuya (Honda R&D)

In this study, white discoloration in automotive interior decorative films was found to be partly caused by void formation induced by the ingress of limonene, a principal component of citrus-based fragrances. Uptake analysis and dynamic mechanical measurements revealed that variations in acrylic composition alter diffusion behavior through differences in chain relaxation characteristics. These differences were shown to influence whitening associated with void formation. Based on these findings, design guidelines for acrylic layers with enhanced chemical resistance are proposed.

Development of an In-Situ Tensile Testing Method for Fire-Resistant Resins at High Temperature and During Combustion
-Comparative Evaluation of Resin Composite Materials for Battery Packs-

Satoshi Enokida･Kouhei Kajitani･Atsushi Yuki (Daikyonishikawa)･Yuki Yamada･Shuhei Yasuda･Junichi Ogawa (Mazda)･Masayuki Okoshi･Asami Nakai (Gifu University)

With the widespread adoption of battery electric vehicles (BEVs), structural safety requirements under fire conditions have become increasingly stringent. However, evaluation methods for the mechanical properties of resins during high-temperature combustion processes have not yet been established. In response, the authors developed an in-situ tensile testing apparatus capable of performing tensile tests during resin combustion. In this study, two types of resin composite materials applicable to battery pack structural components were evaluated. The results demonstrate that the sheet molding compound (SMC), which forms a char layer during combustion, exhibits superior strength retention.

Study on Non-Destructive Evaluation of Fiber Content for Advanced Quality Assessment of Recycled CFRP
-Thermal Diffusivity Measurement Using Active Thermography-

Atsushi Akai (Kyoto University of Education)･Yukihiro Hamada (Toyota Motor)･Yasumoto Sato (Toyota Central R&D Labs.)･Atsushi Mikuni (Toyota Motor)

Recently, recycled carbon fiber reinforced polymer (recycled CFRP) composites, which are made from recycled fibers, have attracted considerable interest. In the quality assessment of recycled CFRP composites, non-destructive evaluation of fiber content uniformity is important. As an indicator reflecting the through-thickness fiber content in CFRP composites, we focused on their out-of-plane thermal diffusivity. In this study, active thermography using a flash lamp was applied to CFRP composites to measure their out-of-plane thermal diffusivity. Furthermore, the feasibility of evaluating fiber content using the out-of-plane thermal diffusivity was investigated.