The Creep of Copper, Copper–10 at.-% Nickel, and Copper–10 at.-% Gold

Abstract

The creep of copper, copper–10 at.-% nickel and copper–10 at.-% gold has been investigated at 600 and 800° C (875 and 1075 K) for stresses in the range 1000–7500 lbf/in² (6·9-51·7MN/m²). Subgrain sizes, etch-pit densities, and the contribution of grain-boundary sliding to creep have been determined and dislocation structures examined by thin-foil electron microscopy. The stress exponent of creep rate for copper and copper–10 at.-% nickel is ≃ 5 and that for copper–10 at.-% gold is ≃ 3. Stress-decrement experiments indicate that the effect of nickel is to reduce the rate of the controlling recovery process, whereas the addition of gold changes the controlling process to one of viscous glide of dislocations.