The crack initiation by cyclic deformation on the two special surfaces of pure Al single crystal is studied. One of the special surfaces is the side-surface containing the active Burger vector, and the other is the top-surface forming the smallest angle with the active Burger vector. The fatigue test results show that many microcracks are initiated on the side-surface upon which no surface topography of persistent slip band is found during cyclic deformation. On the side-surface cracks are short with mean length of about 10 microns and distribute approximately in a similar direction perpendicular to the active Burger vector, while on the top-surface cracks are not so obvious as those on the side-surface. Observations by scanning acoustic microscopy show that the fatigue damage on the side-surface is much deeper than that on the top-surface. A pore model of persistent slip band are suggested.
|Journal||Jinshu Xuebao/Acta Metallurgica Sinica|
|State||Published - Jan 1 1991|
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys