Abstract
Stress-reduction and uninterrupted experiments have been conducted on Al in the temperature range 573-923 K; in performing stress-reduction experiments, stress-reduction ratios ( tau sub(1) - tau sub(2))/ tau sub(1) ranging from 0 multiplied by 05 to 0 multiplied by 75 were used. The stress exponent inferred from stress-reduction experiments, n*, was compared with that obtained from uninterrupted tests, n. On the basis of this comparison three regions of behaviour, were identified. At high temperatures (T greater than or equal to 673 K), n* = n regardless of the value of the stress-reduction ratio. At intermediate temperatures (600 K < T < 673 K), n* = n for large reduction ratios ( greater than or equal to 0 multiplied by 2), whereas n* > n for small reduction ratios ( less than or equal to 0 multiplied by 15); for small reductions, the lower the reduction ratio, the larger the discrepancy between n* and n. At low temperatures (T < 600 K), n* > n for all stress-reduction ratios used.