Development of salt cores prepared by high-pressure squeezing and shooting with inorganic binders has shown a high potential of the

given technology even for high-pressure casting of castings. Strength, surface quality of achieved castings, and solubility in water become

a decisive criterion. The shape and quality of grain surface particularly of NaCl – cooking salts that can be well applied without anticaking

additives has shown to be an important criterion. Thus the salt cores technology can cover increasingly growing demands for casting

complexity especially for the automobile industry.

A wide variety of water-soluble cores are widely used in hollow composite castings with internal cavities, curved channels, and undercuts. Among them, the cores made by adding binders of inorganic salts in the form of aqueous solutions have excellent solubility in water. However, excellent collapsibility is often accompanied by poor moisture absorption resistance. In this study, a water-soluble core with moderate strength and moisture absorption resistance was prepared by hot pressing and sintering the core sand mixture of sand, bentonite, and composite salts, and a tee tube specimen was cast. The experimental results showed that the cores with KCl-K2CO3 as binder could obtain strength of more than 0.9 MPa and still maintain 0.3 MPa at 80±5% relative humidity for 6 hours; the subsequent sintering process can significantly improve the resistance to moisture absorption of the hot pressed cores (0.6 MPa after 24 hours of storage at 85±5% relative humidity); the water-soluble core prepared by the post-treatment can be used to cast tee pipe castings with a smooth inner surface and no porosity defects, and it is easy to remove the core.

A number of technologies is developed that substitute simple metal cores in the high-pressure casting technology. Soluble cores, namely

on the salt basis, represent the highest prospect. The contribution gives the results of the production of salt cores by high-pressure

squeezing and shooting with using a binder. Special attention is paid to the shape of NaCl salt crystals with additives and the influence on

strength properties of cores. A technology of bonding the salt cores is developing. Salinity of circulating water is studied and it is checked

with the aid of electrical conductance.