β Scribed by T Kaji; J Cadek; H Oikawa
No coin nor oath required. For personal study only.
A~traet--Temperature change tests have been done during steady-state creep of polycrystalline aluminum to obtain some fundamental information on the activation energies for parameters related to hightemperature deformation. By the direct passing of a current through a specimen, a temperature increase of 5-20 K was achieved within 0.1-1 s. Immediately after the temperature rise, the creep rate was higher than that expected under the assumption that the activation energy for creep Qc was equal to that for self-diffusion, QD. The apparent Qc immediately after the temperature rise was about 175 kJ/mol. The creep rate became gradually lower and reached, within 1-2 s, the value expected from the relation, Qc-QD = 135 kJ/mol. The experimental results have been discussed by taking into account the apparent temperature dependence of recovery and work-hardening rates during steady-state creep of pure metals.
It is concluded that creep structure depends on temperature even under an identical a/E condition. Upon
π SIMILAR VOLUMES
Abstracts torsion testing under cyclic loading to lo6 cycles. It was learned that carbon-carbon creeps or takes on a permanent deformation, but is resistant to fatigue loading and in general can retain its stiffness and strength up to lo6 cycles. Fiber bundle slipping and re-sticking is believed to