SU531621A1 - Mixture for making molds and cores - Google Patents

Description

Pupverbakepit10 16 Metallurgical Magnesite The remaining Mixture is prepared by ordinary mixing of the ingredients that make it up. Molds are made by pressing, pressing two heated plates (T 25 O - 300) at a specific pressure of 30 kts / cm After pressing, the molds are subjected to calcining; 5, according to the mode; heating up to 32О-550 С with holding up to 2 h; heating up to 90О-950 С with a shutter speed of at least 1 h and cooling with a stove de 300 300 ° C. In tab. 1 shows the compositions of mixtures 1-5, of which mixtures 1 and 2 are known. Table 2 shows the properties of the mixtures and the quality characteristics of the castings. In the process of hot pressing and sintering due to polymerization, pulverbels that form and the core acquire high strength and are easily removed from the tooling. In the process of calcining the odds, due to the destruction of pulverbackel and coal tar pitch, a coke skeleton is formed, providing the required strength to the molds. Density of molds made from the proposed mixture, g / cm Thermal storage capacity, kW CM / i - /; -. hail Shrinking of molds in the process of less than 0.4 rokalki,% 1 -ubin more polluted than 0.4 foot of casting, mm M aximal per microtube, sg / mm Castings S obtained in such forms have good dimensional accuracy and high density. The proposed mixture for the manufacture of molds and cores can be reused with the introduction of fresh ingredients up to 10%,

Ingredient

Magnesite

Liquid glass

M agnesite metal aurgic

Caustic Magnesite

M agni hl orista

Bornp1 anhydride

Water

Coal tar pitch

Pulverbak.ait

T a b l

c a

Content, Un.%

64

70

76

1414

20 16

1O 16

Claims (1)

6O 60 12.0 60 15.0 Claims of the Invention Mixture for the manufacture of casting molds and cores, mainly in titanium casting, including metallurgical magnesite and a binder, characterized in that, in order to solidify the mixture directly in a hot process i a o l ti c a 8,8 330 330 330 snap-in while maintaining its good knock-out and regenerated. As a binder, the mixture contains coal tar pitch and pulverbakelite in the following ratio of ingredients, ses9: Coal tar 14-20 Pulverbakelnt1 0-16 Magnesite metallurgicalEstal.