It was recalled that a model (conventional dislocation theory) was required in order to explain the extremely low shear strength of real metals, as compared with their theoretical strength. However, a dislocation theory which was based upon conventional metallic bonding could not produce a real stress-strain curve. A disbonding theory which was based upon the crystalline π-bonding of atoms could easily explain real stress-strain curves. Many π far-infrared rays emerged from the lattice during disbanding, and were used for re-bonding during plastic deformation and strain-hardening. Anelasticity, the hysteresis effect, the Bauschinger effect and slip-banding during fatigue could be easily explained by the π far-infrared rays and crystallizing π-bonds.

A Note on the Inadequacy of Dislocation Theory (Disbonding Theory). H.K.Oh: Journal of Materials Processing Technology, 2000, 104[1-2], 8-10