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

FIELD: mechanical engineering. SUBSTANCE: method involves manufacturing investment casting from powdered mixture of single-component investment material of 0.1-1.6 mm fraction and sodium chloride of 0.1-0.63 mm fraction. Volumetric ratio of mixture components, %: investment material 75-80 and sodium chloride 20-25. Investment material is dosed in casting mold in an amount providing manufacture of investment castings with 3-10% porosity. Investment material is pressed without preliminary heating by aligning casting mold detachment surfaces. During pressing powdered investment material is caked without substantial phase deformation processes and with formation of open capillary porosity compensating expansion of investment casting during heating thereof in the process of molding from enclosure. EFFECT: increased dimensional and geometric precision of investment castings and ingots. 1 tbl