Plastic Deformation in Ordered Solid Solutions and Its Effects on Physical Properties

摘要

Deformation tests were made of Ni3 Fe and Cu3 Au. Disordered state single crystals show 3 stages deformation as in pure metals. But 1st stage due propagation Luders bands. Stage II linear hardening with slop G/400, G= shear modulus. In ordered state linear work hardening depends on domain size, test temp., crystallographic orientation. Tensile axis rotation agrees with calc. assuming single glide. Deformation tensile axis overshoots symmetry line (100)(111), shows strong latent hardening secondary systems. Strain ageing depends critically stage of deformation. Secondary slip important in controlling plastic deformation ordered Solid Solutions. Formation antiphase boundary tubes explains exptl. results if original model modified with geometrical relationship between primary and conjugate applied stresses and consideration of latent hardening effect. An investigation was made of the dependence alpha on domain size Cu3 Au. Alpha reaches saturation value after no further increase in degree of order. Longer annealing modifies domain size but alpha constant. Activation energy 25 Kcal /mole. continues. An investigation was made of activation enthalpies and volumes for creep in Ni3 Fe in temp. range 40 - 150C, ordered and disord cond. Above 150C, ageing effect interferes, deformation becomes discontinuous. Kinetics of ageing faster in disordered state. Self diffusion of Ni creep controlling at high temp., max. at 72/25 Ni/Fe comp. (Author)