負荷速度と変形について（第1報）多結晶アルミニウムの塑性変形におよぼす負荷速度の影響

抄録

The effect of the loading speed (stress rate), which is varied from 3000 to 10 g/mm²/min on the tensile stress-strain curve and the deformation characteristics was studied up to 3 kg/mm² stress with commercial purity polycrystalline aluminium. An increase in loading speed was found to have a marked effect in inhibiting the initial deformation and in modifying the subsequent stages of deformation. The yield stress, the homogeneity of the plastic deformation all over the specimen, the heterogeneity of the deformation along the direction of slip line and the rate of strain hardening were increased, the space of slip bands and the number of fine structure in each slip bands were decreased with an increase of the loading speed. The results were discussed in the terms of number of the active the dislocation sources N(σ,\dotσ), assumed to be N(σ,\dotσ)=N₀(σ)(1+A\dotσ^m) from the stress concentration facter. It was concluded that the greater the loading speed, the more the obstacles such as the Lomer-Cottrell sessile dislocation were formed.