Comparison of conventional and small punch creep tests of mechanically alloyed Al–C–O alloys

Aluminum alloys reinforced by alumina and carbide particles were tested in small punch creep at temperatures of 623 and 723 K. The alloys were prepared by powder metallurgy route (mechanical alloying) and contained 0.8 wt.% of oxygen and 1 and 2 wt.% of carbon, respectively. The dependence of the time to fracture on the applied force closely resembles the stress dependence of the time to fracture in conventional tensile creep of the same alloys. The force in small punch test and the stress in conventional creep test of the same duration are thus linearly related. A new procedure for estimating the proportionality constant is presented. It is shown that the proportionality constant is dependent on the deflection observed at fracture in the small punch test.