METHOD FOR MANUFACTURING AXIALLY SYMMETRICAL PARTS AND BLANK MAKING PROCESS FOR PERFORMING THE SAME Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely manufacture of disc-like parts having conic, semispherical or other axially symmetrical form of low ductile and hard-to-form materials such as refractory alloys. SUBSTANCE: method comprises steps of locally shaping rolled blank having central and peripheral portions and heat treatment of it; using initial blank of multiphase alloys with structure prepared for superplastic deformation; performing local shaping at controlling thermomechanical conditions. Temperature range is more than 0.4 Melt but lower than temperature of total recrystallization of blank material. Local deformation rate is equal to 10²-10^-3s^-1. Central portion of blank is deformed by compression or by compression and torsion with use of tail spindles. Peripheral portions of lank are rolled by means of rollers having at least three motion freedoms. Heat treatment of parts is realized at heating them higher or lower than solution temperature of second phase or allotropic modification of matrix. Necessary structure of blank is achieved at deformation-heat treatment of it at lowering temperature step by step. Such treatment is combined with preliminarily shaping blank for rolling. EFFECT: reduced labor consumption, enhanced factor of material usage. 34 cl, 14 dwg, 2 tbl, 15 expo