Pulse Current Influence and External Electronic Impact of Brittle Fracture on Metals

 

Prof. O.A.Troitsky

 

1. The current pulses increase plastic deformation preceading to a brittle separation of zincum crystalls, estimated according to specific crystallographic shift ak, on 100-200% at low temperature and on 50-60% at room temperature(for amalgamated zincum). Limit true values of normal p - and chopping t stresses are increased at planes (0001) of cleavages of crystalls, that is a consequent of considerable growth of ak.

    Metallographic analysis of surface chopped off chips destroyed by a current or without a current according to orientation of the main stage of a chip as well as analysis of nature of dependance between normal p - , chopping off stresses and orientation of used crystalls xo, make it possible to draw a conclusion that under the brittle fracture of zincum crystalls by pulse current, edge dislocations play significant part in preparation of a cracks generation on a plane of a basis.

 

2. Under external electronic impact by accelerated electrones with power of 0.55 Mv, a plastic deformation increases on 35-40% that is preceading to a brittle fracture of the same samples. The level of critical normal stresses is augmented on the cleavage planes (0001), the factor of hardening decreases, as well as the level of critical shear stresses is reduced on 15-20%, that testifies to facilitation of start and of duplication of dislocations and removal of internal stresses in metal.

    Thus, external electron impact with power below the threshold of backing-out of atoms and pulse current, applied directly during metal deformation, displace the brittle deformation of a metal to a more late stages of deformation. The limit of cold brittleness is displaced closer to lower temperature that gives way to increase of brittle strength and reliability of a metal at low temperature.