EFFECT OF STRESS ON THE CREEP RATES OF POLYCRYSTALLINE ALUMINUM ALLOYS UNDER CONSTANT STRUCTURE
Technical rept. no. 24
CALIFORNIA UNIV BERKELEY MATERIALS RESEARCH LAB
Pagination or Media Count:
A method is described for studying the dependence of the creep rate of metals on the applied stress under the condition of constant structure. The method was applied to pure Al and to dilute solid solution alloys of Mg, Cu, Ge, Zn, and Ag in Al. The applied stress delta and the creep rate epsilon were shown to be related by the equation epsilon S e -DeltaHRT sinh Beta delta where S is a parameter incorporating structural changes occurring during creep, DeltaH is the creep-activation energy, R is the gas constant, T is the absolute temperature, and B is the reciprocal of the slope of delta vs log epsilon divided by 2.303 Beta was independent of the creep structure for a given material a linear relationship existed between 1Beta and the per cent of alloying addition to Al for a given solute element. The reciprocal of Beta was a function of the low-temperature solid-solution strengthening of the alloys.
- Properties of Metals and Alloys