Microstructural plastic instability of impurity crystals

The effect of the temperature, the concentration of impurities and the density of dislocations upon the plastic instability was studied. A comparison of the theory with the experiments on plastic deformation of an Al-Mg alloy permitted to predict the temperature and the stresses at which this effect appears. It was shown that sufficiently large stresses applied to the mobile dislocations cause them to interact with Weakly fixed seaments to initiate mobile dislocation micro-avalanches. The motion of dislocation macro-avalanches, appearing after the micro-avalanches, leads to an intermittent macroscopic deformation of the specimen