PLASTICITY OF BETA-BRASS SINGLE-CRYSTALS AT LOW-TEMPERATURES

The plasticity of beta -brass single crystals, whose axes lie relatively near the left bracket 001 right bracket direction, was investigated at temperatures ranging from 77 degree K to room temperature. It was found that the flow stress at 0. 2% strain did not continuously increase with decreasing temperature but showed a peak value at about 195 degree K. The behavior is different from the temperature dependence of flow stress in ordinary bcc metals and alloys. This is explained in terms of an increase in flow stress due to the interaction between different slip systems or occurrence of cross slip from basic slip planes left brace 110 right brace and left brace 112 right brace . Below 115 degree K, the temperature dependence and the strain rate sensitivity of the flow stress are similar to those of ordinary bcc metals and alloys.