Fundamental Property of Metals – Grain Boundaries Phase Transition as a Basis of Nanostructured Layers, Materials and Composites Production
The obtained generalized equation for description of a fundamental property of solid crystalline materials i.e. first-order phase transition of the grain boundaries with formation of two-dimensional liquid has been used for calculating of transition temperature of any metals, which value lies in range 0.55 – 086 of melting point. Based on these conclusions to develop strategies for effective forming of coatings by synthesis of nitrides and carbonitrides on surface layers of hard metals and chromium steels have been made. It was shown the hardening of thin surface layer (0.1-0.5mm) due enriched of a nitrides in steels and carbonitrides with diamond like structure and strengthening the following layer by recristallization of W carbides in WC-Co and WC-TiC-Co hard metal. These result to increase of alloys hardness, ductility, and resistance to wear and decrease of sensibility to fragile rupture. Industrial tests have been made.
Jian-Feng Nie and Allan Morton
Y.A. Minaev "Fundamental Property of Metals – Grain Boundaries Phase Transition as a Basis of Nanostructured Layers, Materials and Composites Production", Materials Science Forum, Vols. 654-656, pp. 1852-1855, 2010