Improvement of Mechanical Properties of Cast Ceramic Cores Based on Ethyl Silicate

The aim of the paper is experimental verification of the influence of the composition of the ceramic mixture on the mechanical properties of cast ethyl silicate cores. Cast ceramic cores have a great potential in the production of complex castings, especially in the field of hydropower. However, the disadvantage of the cast ceramic cores is their low strength during cores removing from the core box and handling with them. The research is focused mainly on the possibilities of increasing the handling strength of the cores during removal from the core box and after their ignition. The paper investigates different ways of increasing the strength of cast ceramic cores by adjusting the composition of the ceramic mixture. Further, the research verifies the possibility of increasing the strength of ceramic cores by adding synthetic fibers to the ceramic mixture. The paper also contains the results of measuring the strength of the cores after impregnation with a solution of phosphorous binder and subsequent annealing.