References: 10 tit.

Both microstructure and generation of severely deformed layer on metals and alloys in sliding wear under condition of scoring have been studied. As shown, the subsurface layer deformation is by propagation of both sliding-induced strain fields and frictiongenerated heat waves. Such a combination of factors results in generation of a microstructure fully consisting of nanosize grains and subgrains arranged in sublayers so that they are capable of shear with respect to each other. Increasing the normal contact load leads to an instability generated by the strain incompatibility between the subsurface nanocrystalline grain layer and underlying base metal. This instability results in a crossover to the higher deformation scale level, which defines both new strain penetration depth and an occurrence of the catastrophic wear.