パルス通電焼結を応用した疲労寿命延命手法の可能性

抄録

The fatigue life prolonging of an aging advanced building is currently needed. In prolonging fatigue life, it is important to reduce the rate of progress of internal fatigue cracks. The rate of fatigue crack propagation is evaluated by using the effective stress intensity factor which is the ratio of stress at opening and maximum stresses. Based on the Paris law, if the effective stress intensity factor decreases, the rate of progress decreases. Therefore, from the viewpoint of fatigue life prolongation, attention has been paid to a method of reducing the effective stress intensity factor in recent years. In this study, a mixture of fine particles and oil was used. Here, it is necessary to select the particle diameter according to the crack length and external force. In this research, we applied pulse current sintering to have no particle diameter dependence. At first, copper fine particles were sandwiched between two iron bars and subjected to pulse current sintering and bonding. In order to confirm the bonding state, the cut surface was observed measured using Scanning Electron Microscope (SEM) and Energy dispersive X-ray spectrometry (EDS). The SEM observation result shows that micro-voids were observed in the vicinity of the junction interface between iron and copper. From the EDS observation results, it was confirmed that both iron and copper elements were present.