Influence of silica sand on surface casting quality

The current casting production of castings brings increased demands for surface and internal quality of the castings. Important factors, that influence the quality of castal components, are the materials used for the manufacture of moulds and cores. For the preparation and production of moulds and cores, in order to achieve a low level of casting defects, then it used a high quality input materials, including various types of sands, modified binders, additives, etc. However, even the most expensive raw materials are not a guarantee to achieve the quality of production. It is always necessary to choose the appropriate combination of input material together with an appropriate proposal for the way of the production, the metallurgical treatment of cast alloy, etc. The aim of this paper is to establish the basic principles for the selection of the base core mixtures components - sands to eliminate defects from the tension, specifically veining. Various silica sand, which are commonly used in foundries of Middle Europe region, were selected and tested.