粒子強化およびウィスカ強化アルミニウム基複合材の高温における微小疲労き裂の発生と伝ぱ(<特集>高温強度)

概要

論文の詳細を見る
Successive process from fatigue small crack initiation to propagation in two kinds of aluminum base composite materials was studied in comparison with long crack growth behavior at high temperature: One is an AIN-particulate reinforced composite and the other is a SiC-whisker(SiCw) reinforced 6061 alloy composite. The results obtained were also compared with that of a traditional heat-resisting aluminum alloy, AC8A. It was shown that the fatigue crack in the both composite materials easily initiated from the region where the reinforcement phase, AIN particulate or SiCw, gathered with high density. Like to general polycrystalline metallic materials, some noteworthy phenomena, which indicate the lack of similitude between small and long cracks, were seen in the small crack propagation process in the both composites: the small cracks grew even at the lower stress intensity factor range than the long crack threshold, and they exhibited higher growth rates than the long cracks. It was also shown that with respect to the effect of reinforcement the small cracks sometimes behaved with conflicting manner to the long cracks. These experimental evidences indicate the importance of studies on small fatigue crack propagation.
社団法人日本材料学会の論文
1995-01-15