Deformational nanostructuring and treatment of metallic materials

Abstract

Theoretical and practical aspects of the production and treatment of nanomaterials are presented. Metals are used to show the main evolutionary stages of the matrix structure of metallic materials during deformation and the factors influencing the reduction of grain size. The formation mechanisms of small-sized grains during cold and hot deformation are studied. An equation is developed that allows the calculation of the average size of cells in the process of formation—predecessors of small-sized grains—depending on the accumulated deformation and the scale factor. Dispersion-hardening nickel alloys are used to demonstrate the possibility of fundamental control over mechanical properties from high heat resistance to superplasticity and, inversely, as a result of deformational thermal treatment, leading to a direct and reverse inversion of nano- and micro-sized intermetallic particles and the transformation of their boundary type from coherent to incoherent. The variation in the microstructure and mechanical properties of dispersion-hardening alloys is considered for the production of key components such as the discs and shafts of gas turbine engines.