METHOD FOR MAKING ALUMINIUM CASTINGS Russian patent published in 2001 - IPC

FIELD: foundry, namely processes for casting thick-wall, complex-shape, large-size aluminium castings by autoclave method. SUBSTANCE: method comprises steps of making casting mold, for example of cores by well known process and assembling it to block; placing casting mold to autoclave; refining aluminium melt, modifying it and pouring to casting mold placed in autoclave; sealing casting opening of autoclave after pouring and creating excess pressure up to 5 ± 0.5 at; achieving maximum effect for lowering gaseous porosity due to rapid filling of autoclave with air. Relation of time period t1 from termination of pouring casting mold until beginning of applying excess pressure to time period t₂ from beginning of applying excess pressure until achieving its maximum value consists 1 : (1-1.5). Minimum relation t₁/t₂ is provided at maximum volume of casting mold and at minimum volume of autoclave. Maximum effect is provided when volume of casting mold consists 40-60% of inner volume of autoclave. EFFECT: enhanced density of castings due to lowered gaseous porosity. 2 cl, 2 tbl