| 摘要 |
FIELD: precision instrument making. SUBSTANCE: method involves locating thin-walled hemispheres with large outer diameter in hemispherical depressions of welding punches mounted in centering member and made from material with thermal expansion coefficient less than that of hemisphere material, with punch depression diameter being less than that of hemispheres; fixing welding members one relative to the other by biasing them through axial pressure; smoothly heating devices carrying hemispheres to welding temperature and providing isothermal holding, with welding temperature exceeding temperature at diameter coincidence points and, as a result of difference between thermal expansion coefficients of hemispheres and punch materials, thermal tension pressure creating radial stresses on hemisphere surfaces being developed. Material and configuration of punches are selected such that punch strength value exceeds force value required for plastic deformation of hemispheres. Welding temperature is selected in accordance with hemisphere material recrystallization temperature. As a result material structure modification occurs due to radial orientation of grains and, consequently, radially oriented thermal tension stresses. EFFECT: improved isotropy of rotor material and enhanced reliability in operation of ball gyroscope rotors due to nature and mechanism of structure modification. |
