| A review is given in honor of Ilya A. Ovid'ko beginning from a mutual interest in disclinations. The main part of the review, however, is based on association of dislocation pile-ups and the Hall-Petch relation for an inverse square root of grain size dependence of cleavage fracturing. Important thermal influence is considered. Special attention is given to small pile-up characteristics associated with nanopolycrystalline material behaviors. Other topics include: (1) the ductile-brittle transition; (2) the ductile true fracture strain; (3) the fracture mechanics stress intensity; (4) hardness; (5) creep; and, (6) fatigue behaviors. Experimental measurements are presented for a wide range of materials. |
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