The paper presents the results of research on the impact of impurities in the feed ingots (master heat) on the precipitation of impurities in
the ATD thermal analysis probe castings. This impurities occur mostly inside shrinkage cavities and in interdendritic space. Additionally,
insufficient filtration of liquid alloy during pouring promotes the transfer of impurities into the casting. The technology of melting
superalloys in vacuum furnace prevents the removal of slag from the surface of molten metal. Because of that, the effective method of
quality assessment of feed ingots in order to evaluate the existence of impurities is needed. The effectiveness of ATD analysis in
evaluation of purity of feed ingots was researched. In addition the similarities of non-metallic inclusions in feed ingots and in castings
were observed.