| The relation between formation and distribution of slip bands in the grains of aluminum polycrystals (purity: 99.9%) and crystal orientation of each grain have been studied after tensile fatigue stressing of the samples. Grains of the samples were grown to the size of 1.5∼3.0㎜ diameter by heat treatment. Crystal orientation and Schmid factor of each grain were determined by means of Laue back reflection. Cyclic tensile stresses were applied to the samples between 189 and 47ｇ/㎟ or 198 and 32ｇ/㎟ at a low frequency of 70 cpm, and the formation and distribution of slip bands were observed by optical microscope after the cyclic stressing of 10², 10³, and 10⁴ cycles. As the value of Schmid factor of a grain was increased, the number of fatigue cycles, in which slip bands are formed, was decreased, Not any slip bands were found in the grains of low Schmid factor values, such as 0.34 and 0.37, even after 10⁴ cycles. |
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