High energy rate modification of surface layers of conductors

Multimicrosecond, high power density current pulses have been employed in a study of the surface response of railgun rail materials. Many of the surface transformations observed appear to result from self-quenching effects. The pulse heating produces a hot skin while the specimen interior remains cold. The hot skin is in intimate thermal contact with the cold interior. These conditions result in a rapid self-quench. The thermophysical properties of the materials affect the extent of the surface modification and the level of damage that results from pulsed joule heating.