Patent UA-105845-C2 (UA)
Title: Method for determination of characteristic of mechanical stability of structural titanium alloy
IPC: G01N3/00
Filed: 2012-10-25
Abstract: The invention relates to the field of non-ferrous metallurgy, in particular to the method for determination of the characteristic of mechanical stability of structural titanium alloy (CTA). The method for determination of the characteristic of mechanical stability of structural titanium alloy includes operations of stretching a standard smooth cylindrical sample along one axis in temperature interval from 77 K to 293 K, determination at that of the basic mechanical characteristics, calculation of the values of intensity of stresses of destructionand relative contraction of the sample, plotting experimental dependences of the resistance to plastic deformation in the area of non-uniform deformationcharacterized by keeping the property of linearity or presence of break, at that the angle if inclination of the dependence is increased, with determination of the group of the alloy depending on the ratio of the values of characteristics of deformation strengthening at deformations smaller and comparable to the uniform one, determination of the characteristics of deformation strengthening for each group of the CTA, with plotting additional dependences that relate the given value of equivalent deformationto the characteristics of deformation strengthening or combination of those in the area of uniform and non-uniform deformation for each group, of constructional titanium alloys, with determination of the characteristic of mechanical stabilityof constructional titanium alloy according to its attribution to a given group by the values of basic mechanical characteristics, like:- relative yield limit of the CTA, MPa,- breaking point of the CTA, MPa,- relative contraction after destruction of the sample of CTA, in parts:- for constructional titanium alloys of the 1-st group:,where:- characteristic of deformation strengthening of CTA:- relative uniform contraction of the CTA sample, in parts,,- empirical coefficients;- for constructional titanium alloys of the II-d group:,where:- real stress at breakage point of CTA, MPa,,,,,- empirical coefficients,- temperature of tests of the CTA, K, at that:- characteristic of deformational strengthening of CTA,- real uniform deformation of CTA,- real deformation of destruction of the CTA sample,- empirical coefficients. The invention provides development of general method for determination of the characteristic of mechanical stability for a broad range of structural titanium alloys according to attribution of those to a given group in interval of temperatures of tests from 77K to 293K, increase of accuracy of evaluation of ability of CTA to oppose transition to friable state , and to perform complex evaluation of the properties of those in broad range of changes of characteristics of strength and plasticity with higher self-descriptiveness. Accuracy of determination of the characteristic of mechanical stability by the method proposed is enough for engineering calculations and for scientific investigations as well, and the dependences obtained for determination of mechanical stability are invariant to different combinations of the properties of strength and plasticity of the CTA and the modes of thermal treatment and temperature of testing.