Initiation and Growth Behavior of Small Surface Fatigue Cracks on SiC Whisker Reinforced Aluminum Composite

SiC 휘스커 강화 알미늄기 복합재료의 미소 표면 피로균열의 발생 및 진전거동

Choe, Yeong-Geun;Lee, Taek-Sun;Kim, Sang-Tae;Seo, Chang-Min;Lee, Mun-Hwan

  • Published : 2000.06.01


Reversed plane bending fatigue tests were conducted on SiC whisker reinforced aluminum composite which were consolidated by squeeze casting process. Initiation and growth of small surface fatigue c racks were investigated by means of a plastic replica technique. The fatigue crack initiated in the vicinity of SiC whisker/matrix interface. It was found that a fatigue crack deflected along SiC whisker and grew in a zig-zag manner microscopically, although the crack propagated along the direction normal to the loading axis macroscopically. The coalescence of micro-cracks was observed in the tests conducted at high stress levels, but were not evident in tests in which lower levels of stress were applied. Due to the coalescence, a higher crack growth rate of small cracks rather than those of long cracks was recognized in da/dn -ΔK realtionship.


Crack Initiation;Small Surface Crack;SiC Whisker Reinforced Aluminum Matrix Composite;Bending Fatigue Test;Stress Intensity Factor Range


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