METHOD OF PROCESSING THE BLANKS FROM γ+α HYPEREUTECTOID ALLOYS Russian patent published in 2001 - IPC

FIELD: plastic metal and alloys processing, particularly, plastic processing of alloys based on titanium aluminate TiAl (γ+α₂ phase) and γ (Ti₃Al phase) produced by casting or by method of powder metallurgy. SUBSTANCE: method includes heating and deformation within temperature interval of 700-Tc, where Tc is temperature of eutectoid conversion at rates of α₂ for i stages, for n transitions at each stage with 10^-4-10^-1 s^-1 total degree of reduction ensuring reduction of grain size due to recrystallization. In this case, temperature Ti and reduction rate Σε of blank at each stage are determined by results of tests of Ni specimens having size of grains/colonies ε_i. In this case, d_i is attained by single-axed compression under isothermal conditions within said temperature-rate interval with consideration of size of recrystallized grains and specific recrystallization volume. Number of stages is determined on the basis of successive reduction of size of grains in initial blank to required value. The proposed method allows to produce homogeneous fine-grain microstructure up to 0.1 mcm. EFFECT: higher efficiency. 28 cl, 4 dwg, 2 tbl