METHOD FOR INCREASING THE THERMAL STABILITY AND MECHANICAL PROPERTIES OF NANO ultrafine nonferrous alloys (OPTIONS)

摘要

1. A method for improving the thermal stability and mechanical properties of nano ultrafine nonferrous alloys, comprising quenching, formation of ultrafine structures by equal-channel angular extrusion, heat treatment of ultrafine alloy, characterized in that the equal-channel angular extrusion is carried out prior to grinding grain structure of the alloy to a size d, calculated by formula: d = 4bG / π (1-ν) (σ-σ), where b - Burgers vector (m), G - shear modulus of the metal (MPa), ν - Poisson's ratio of the metal, σ- external applied stress (MPa), σ- internal stresses due to nonequilibrium grain boundaries (MPa), and heat treating the ultrafine alloy is carried out in two stages by the low-temperature annealing and high temperature otzhiga.2. A method according to claim 1, characterized in that the low-temperature annealing performed at a temperature, which is calculated by the formula: where D- pre-exponential factor (m / s) in the expression for the grain boundary diffusion coefficient; Q- pre-exponential factor and the activation energy for grain boundary factor expression diffusion (kT); ρΔb - initial (before annealing), the density of defects in the grain boundary of ultrafine material; δ = 2b - the width of the grain boundary (m); t - time of annealing (c); k - Boltzmann's constant (J / k) .3 . A method according to claim 1, characterized in that the high temperature annealing is carried out in the temperature range 350-600 ° C for up to 0.1-10 p.4. A method for improving the thermal stability and mechanical properties of nano ultrafine nonferrous alloys, comprising quenching, formation of ultrafine structures by equal-channel angular extruded