METHOD FOR MAKING INVESTMENT PATTERNS Russian patent published in 2004 - IPC

FIELD: machine engineering, namely manufacture of castings with use of investment patterns.

SUBSTANCE: pattern is made of material containing pellets of ammonium nitrate clad with pattern composition and having fraction size 0.1 - 2.5 mm. Material includes component at next relation by volume: pattern composition, 10 - 65%; ammonium nitrate, 35 - 90 %. Pattern material is metered into press-mold in quantity providing manufacture of patterns with porosity 3 - 10%. Pattern material is pressed without preliminary heating due to matching parting surfaces of press-mold. At pressing pattern material is sintered practically without phase deformation processes with formation of open capillary porosity which compensates temperature expansion of pattern at melting it out of ceramic mold.

EFFECT: enhanced dimensional and geometry accuracy of castings and patterns.