Physical theory and a new scheme of brittle transition in crystals

The existing approaches to the phenomenon of cold brittleness in microstructural models and brittle transition criteria are briefly examined. A new brittle transition scheme is proposed which allows for the thermally activated dislocation process of the interaction of stable (equilibrium) microcracks with short-range obstacles or long-range barriers of varying nature and efficiency, which control macroscopic changes in the dynamic fracture parameters and gradual degradation of the plastic properties of partially covalent metal crystals at low temperatures.