Prediction of Critical Threshold Stress Intensity Range for Crack Growth

Gyoko Oh (Tokyo Roki)

The initiation and propagation of cracks near the fatigue limit in notched steel plate samples were observed and analyzed using fracture mechanics parameters. The threshold stress intensity range had a good power function correlation with the effective notch length, but it depended on the notch length and did not reach a constant value. By identifying and using the critical power exponent, a prediction model was proposed for the critical threshold stress intensity range that becomes a constant value.

Development of Non-Heat Trated Aluminum Alloy for Body Structure Applied Integrated Casting

Jae Sun Lim･Dong Ha Kang･Tae Seong Lim･Jun Beom Lee (Hyundai Motor)

Recently, as environmental regulations of automobiles and development of electric vehicles are actively progressing, demands for improving fuel efficiency are increasing. Among them, in order to minimize parts and reduce assembly costs, the integrated development of aluminum bodies is being actively developed by various global companies. Many problems are expected to apply large die casting, in body structure, two fundamental challenges must be overcome. First, the aluminum-integrated cast must satisfy the stability of vehicle collision behavior. Second, it is recognized as an important task to be solved by reducing the cost of post-processing.
By developing an non-heat-treated aluminum alloy for a body considering recyclability, we have prepared a foundation to contribute to the reduction of carbon generation by responding to the development of large-scale vehicle body parts.

Reduction of Heavy Rare Earths by Composite Magnets for IPM Motors

Shunsuke Takahashi･Yutaka Sasaki (Hino Motors)

Magnets with high coercivity are often used for IPM motors. However, demagnetization resistance is usually required at the ends of the magnets. If only the center part of the magnet is replaced with a low coercivity magnet, the amount of heavy rare earth elements can be reduced.In this study, we verified whether the performance can be maintained after the magnet replacement with the conditions (including inverter conditions) other than the magnet material remaining unchanged.

Prevention of Temperature Reduce of Exhaust Gas Catalyst with Latent Heat Storage Material

Junji Itou･Tetsuro Naito･Koichi Yamaguchi･Kazuyuki Shiratori (Nissan Motor)

Towards to realize carbon neutral at 2050, Nissan forwards electrification such as series hybrid system e-POWER.
It would be concern that performance of exhaust gas catalyst might be sufficient if temperature of exhaust gas catalyst would reduce while engine stops.
To solve this concern, Nissan have developed new catalyst with latent heat storage material to prevent temperature reduce of exhaust catalyst.