METHOD AND DEVICE FOR DIRECTLY PRODUCING AN INVESTMENT CASTING MOLD FOR CASTINGS MADE OF METAL

The invention is directed to a method for directly producing a lost mold by machining a sand mold made with curable binders. The invention is intended in particular to decrease tool wear and to increase dimensional accuracy and exactness in the reproduction of the mold, in that a mold blank (1) to be machined is constructed by means of a pattern set (4) with the use of a variable or fixed molding box (2) and includes in its volume the desired contours of the casting mold and a machining allowance for the milling of the mold material. After filling of the molding box (2) with curable foundry mold materials, curing, and removal from the mold, the mold blank (1) is transformed into the casting mold by removal of the machining allowance by high-speed machining, milling or 3-D machining of freeform surfaces. The invention concerns lost molds for metal castings and the fabrication of casting prototypes and odd parts in the range of small-and medium-sized articles and production runs.