THREE-DIMENSIONAL CRYSTALLIZING $\pi$-BONDINGS AND WEAR OF METALS

Phenomelocial evidences for three-dimensional crystallizing $\pi$-bondings are investigated in case of the soft layer very near the suface of the metal , the surface layer of certain crystaline thermoplastics. the increased contact area of the metalic frictional interface and the delaminated sheet-like wear particles of the metal . The wear mechanisms are the cracks at the boundaries of the grains and their propagations parallel to the surface. The cracks are made by the reorientations of the atoms in the grains and the rotations of the grains.