METHOD OF MANUFACTURE OF DISPOSABLE PATTERNS Russian patent published in 2002 - IPC

FIELD: mechanical engineering; investment casting. SUBSTANCE: pattern is manufactured from powder-like mixture of pattern composition of 0.1 to 1.6 mm fraction and sodium carbonate fraction of 0.01 to 0.3 mm. Ratio of mixture components by volume is as follows: model composition, 75 to 80% and sodium carbonate, 20 to 25%. Pattern material is metered in mold in the amount sufficient for obtaining patterns at porosity of 1.5 to 3%. Pattern material is pressed without preheating by matching parting surfaces of mold in vacuum of 0.1 MPa. In pressing, powder pattern material is sintered without phase deformation processes forming open capillary porosity which compensates for expansion of pattern in the course of heating during extraction from ceramic envelope. EFFECT: enhanced dimensional and geometric accuracy of patterns and castings. 1 tbl