Abstract

Recrystallized, rolled rods of the two conductor alloys were deformed in continuous torsion tests between 200 and 500C̕ and 0.02 and 5 s -1 , and in interrupted torsion tests at 400 and 450C̕, and 0.1 and 1.0 s -1 . The flow stresses were found to depend on the strain rate through a hyperbolic sine function with exponents of 3.1 and 3.5, and on temperature through an Arrhenius term with activation energies of about 260 kJ/mol, much greater than Al. Flow stresses were considerably higher than commercial Al at 200C̕ and 300C̕, consistent with their resistance to creep softening in that range. The strengthening depends upon the dispersion of the eutectic rods which were refined by Properzi casting, were fractured and dispersed by rolling, and have very low solubility. The hot ductility increased with temperature but decreased with strain rate and with rising levels of alloy addition. The strain to fracture varied inversely with the strain to steady state and hence the level of dynamic recovery. In interrupted testing, fractional softening increased with rise in temperature or hold time, or decline in strain rate. With repeated passes, the strength of the alloys declined substantially compared to continuous testing.