METHOD OF PRODUCING GRAPHITE MOLD TO PRODUCE CASTINGS FROM REFRACTORY AND CHEMICALLY ACTIVE ALLOYS Russian patent published in 2017 - IPC B22C9/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to production of elements of molds and cores by layer-wise three-dimensional jet printing for production of shaped castings from titanium alloys by centrifugal and gravity casting for further production of cast parts of aircraft, helicopter and rocket engines, as well as cast parts for nuclear power engineering or chemical industry. Elements of molds and cores are made from crystalline graphite powder fraction 0.05–0.2 mm, consisting of particles with compact non-lamellar shape, which if necessary is mixed with aluminium powder in amount of 3–7 wt%. Binder used is liquid thermosetting resin. Printing of elements is performed by application of a support layer of powder material, on which successively layer by layer are deposited layers of graphite powder. On each applied layer in required areas of at least one printing head binder is applied to form bound in required points of each layer of graphite powder. Surface of each layer is exposed to radiation from an infrared source for evaporation of volatile components of binder and its partial polymerisation. After obtaining printed object, corresponding to the element being made, it is heated to temperature of 250–350 °C without removal from surrounding non-bonded graphite powder for complete polymerisation of binder and sintering at temperature 900±50 °C in vacuum or inert atmosphere in support filler from material which is inert with respect to titanium and graphite.

EFFECT: possibility of making components of molds and cores by layer-wise three-dimensional jet printing for production of castings from refractory and chemically active alloys.

1 cl, 8 dwg