METHOD FOR MANUFACTURE OF REMOVABLE INVESTMENT PATTERNS Russian patent published in 2002 - IPC

FIELD: mechanical engineering. SUBSTANCE: method involves manufacturing investment pattern from powdered investment pattern mixture composition of 0.1-1.6 mm fracture and boric acid of 0.01-0.0 mm fraction, with volumetric ratio of components being, %: investment pattern composition 75-80%, boric acid 20-25; providing dosed dispensing of investment pattern material into mold in an amount allowing production of investment patterns with porosity of 1.5- 3%; pressing investment pattern material without preliminary heating by aligning detachment surfaces of mold under vacuum of 0.1 MPa. During pressing powdered investment pattern material is caked without substantial development of phase deformation processes with formation of open capillary porosity compensating investment pattern expansion in the process of heating during melting from ceramic enclosure. Method is used for investment casting. EFFECT: increased efficiency by improved dimensional and geometric precision of investment patterns and ingots. 1 tbl