Rozpustná slévárenská jádra na bázi anorganických solí

Abstract

This dissertation discusses a quite new and original method of application of disposable salt cores for pre-casting of holes and cavities in high pressure die castings in aluminium alloys. These cores are prepared from pure crystalline salts, (inorganic in origin), and composite mixtures which are water soluble. Solubility of the cores allows re-crystallization of the salts from the aqueous solution thereby creating the conditions to achieve an ecological closed loop core production system. The dissertation also discusses the development and manufacture of salt cores using high pressure pressing and shooting in order to achieve high strength cores with good bending strength, stability against moisture absorption, dimensional accuracy and low surface roughness of the pre-cast holes. All this was predicated on a test casting, allowing technological changes, particularly the velocity of the metal in the gates, holding pressure and position of injection against salt cores (erosion of cores).The kinetics of dissolving the cores in water was also investigated including the subsequent energy efficiency of re-crystallization from the salt solution. The conclusion is dedicated to the preparation and verification of salt cores to produce a real casting of a turbocompressor in the foundry of the joint-stock company of Kovolis Hedvikov, a.s. Třemošnice.