抄録
Self-healing fiber-reinforced ceramics (shFRCs) are widely expected to be advanced structural materials for aerospace engineering. The most attractive feature of shFRC is ultra-high reliability and life time induced by self-healing during service. However, there has still been lack of evaluation methodology on design stress, which is necessary to be put to practical use as structural materials, because the self-healing occurs under completion to the crack propagation induced by service stress. The present study aims to establish the experimental method to clear the completion between crack self-healing and crack propagation. Furthermore, the maximum stress under which the composite can safely self-healing (Limit load stress) was defined as the design stress of self-healing materials. Actually the limit load stress of alumina fiber reinforced self-healing alumina containing SiC interlayer as healing agent, which is typical shFRC, was investigated at 1100 ℃ in the present study. The experimental set up revealed that the sfFRC can heal under the stress of 80 % of cracked strength, under which the considerable crack propagation occurs without self-healing (the competition at room temperature). Therefore, limit load stress of shFRC at 1100℃ was succeeded to be determined to be 80 MPa.
