PROCEDURE FOR GROWTH OF MONO CRYSTAL OF SAPPHIRE ON SEED LEFT IN MELT DURING GROWTH

摘要

FIELD: metallurgy.;SUBSTANCE: procedure is based on comparison of current parametres of growth of mono crystals at continuous control of weight and constant speed of crystallisation with results of periodic calculations by mathematic formulas describing non linear processes of motion of heat field and front of crystallisation in volume of crucible and at successive change of process parametres of growth. Here is disclosed complex chart of dependencies on time, weight and pulling speed of growing mono crystal at fore part growing. Charge and scull are degassed in vacuum chamber before charge melting.;EFFECT: production of mono crystals of exceptionally big size of cylinder shape due to elimination of radial non-symmetry of temperature field near front of crystallisation; facilitating structural perfection of mono crystal in whole volume owing to constant speed of crystallisation.;6 dwg, 1 ex