Electroplastic effect under the simultaneous superposition of electric andmagnetic fields

In recent years a number of models were proposed in which the electroplasti c effect in the process of thermal fluctuation motion and generation of dis locations was considered to be a result of lowering potential barriers by t he electromagnetic field. The experiments carried out so far reveal the sur face character of the electroplastic deformation. To test the effect, the f ree surface has been perturbed by an electromagnetic field. The deformation of a bismuth crystal in response to application of mechanical stress and c oncurrent constant magnetic field and an impulse electric current has been studied. To illustrate the deformation process in single crystals of bismut h under the simultaneous effect of the electric and magnetic fields, a spec ial device was designed as a supplement to the standard microhardness measu ring equipment. There are two factors that increase plasticity in the case of the concurrent application of magnetic and electric fields. The first on e is the damped elastic sonic vibrations caused by the Ampere force. In the case of deformation by twinning, these vibrations result in an increase of wedge-shaped twin around the imprint of the diamond indentor. The second f actor is the electric charge on the free surface. The electric charge on th e cleavage face increases the run of the twinning dislocations. (C) 1999 Am erican Institute of Physics. [S0021-8979(99)07617-3].