METHOD AND APPARATUS TO PRODUCE CRYSTAL HOLLOW PIECES Russian patent published in 1995 - IPC

FIELD: precision equipment. SUBSTANCE: to produce pieces with accurately given dimensions directly from melt, using form-creating means they provide close fitting of melt column to form-producing rod due to creation of additional pressure of melt. Crystal growing is exercised under temperature of horizontal surface of form-creator not less than and upper butt of protruding over it rod not over than temperature of melt crystallization with location of crystallization front in height in limits between horizontal surface of form-creator and upper butt of protruding over it rod. Apparatus to realize the method has container for melt, movable rod with seed-holder and melt nonwettable material, in which rod with one given form of cross-section is protruded over its upper horizontal surface by 1 - 4 mm. Apparatus also has mounted on rod piston, lifting melt to make additional pressure. EFFECT: methods and apparatus to produce crystal hollow pieces are used in production of monocrystal capillaries and waveguides. 2 cl, 3 dwg