  Recently the hierarchical defect substructures were observed experimentally
in several metals and alloys before and after fracture. The general models of
crystal defect aggregation with appearance hierarchical defect substructures
are proposed and considered in the wide range of scales. Their general group
analysis is performed, and symmetries of the governing equations are
identified. The models of defect aggregate growth are considered for several
partial cases and compared with classical Lifshitz-Slyozov-Wagner theory of
coarsening, Leyvraz-Redner scaling theory of aggregate growth, etc. The reduced
equations of new models are generated and solved, and the general scaling
solutions are given. The results obtained are illustrated by preliminary
simulations.
