[The influence of different conditions of refractory mold preparation on precision of casting of Co, Cr, Mo alloys].

The following hypothesis was made: different conditions of preparation and heat treatment of refractory mold change its physical and mechanical characteristics which is of great importance for the precision of casting of Co, Cr, Mo alloys. To prove this hypothesis measurements of setting time, setting and thermal expansion and transverse strength were performed regarding the relationship between the powder and the liquid of investment. The research was carried out on "Politerm C", "Rema Exakt" and "Widerit" investments. The obtained results proved the hypothesis that different conditions during the preparation of refractory mold had a certain influence on the quality of casting of Co, Cr, Mo alloys. The domestic investment was approximately of the same quality as the tested investments of foreign origin.