Creep of metal-type organic compounds—I. Pure polycrystals and particle-hardened systems

Abstract

The creep of polycrystalline camphene and succinonitrile was studied in uniaxial compression at temperatures of 273 and 293 K. Succinonitrile exhibited classic power-law creep under all conditions with a stress exponent of 5.4±0.1. Camphene showed power-law creep at higher stresses with an exponent of 4.7±0.1. However, at lower stresses, camphene exhibited diffusion creep. The minimum applied stress in each material was not sufficiently low to identify a threshold stress for creep. The creep of particle-hardened alloys was modelled using camphene and succinonitrile containing a dispersion of alumina particles of average size 0.4 μm. The volume percentage of alumina was varied from 0 to 6.6% for camphene-alumina and from 0 to 4.8% for succinonitrile-alumina. Creep measurements were made at 273 and 293 K. In all cases, creep was found to obey a power-law. The stress exponent increased by factors of up to 3 for camphene-alumina, and 2 for succinonitrile-alumina. The data could be described with the same stress exponent as that of the unalloyed systems by subtracting a back stress from the applied stress.