TY - JOUR N2 - The paper presents the results of evaluation of the metallurgical quality of master heat ingots and of the identification of non-metallic inclusions (oxides of Al., Zr, Hf, Cr, etc.), which have been found in the shrinkage cavities formed in these ingots. The inclusions penetrate into the liquid alloy, and on pouring of mould are transferred to the casting, especially when the filtering system is not sufficiently effective. The specific nature of the melting process of nickel and cobalt alloys, carried out in vacuum induction furnaces, excludes the possibility of alloy refining and slag removal from the melt surface. Therefore, to improve the quality of castings (parts of aircraft engines), it is so important to evaluate the quality of ingots before charging them into the crucible of an induction furnace. It has been proved that one of the methods for rapid quality evaluation is an ATD analysis of the sample solidification process, where samples are taken from different areas of the master heat ingot. The evaluation is based on a set of parameters plotted on the graph of the dT/dt derivative curve during the last stage of the solidification process in a range from TEut to Tsol. L1 - http://www.journals.pan.pl/Content/87024/PDF/01_paper.pdf L2 - http://www.journals.pan.pl/Content/87024 PY - 2012 IS - No 4 DO - 10.2478/v10266-012-0099-5 KW - ATD thermal analysis KW - Nickel superalloys KW - Master heat ingot KW - solidification KW - non-metallic inclusions A1 - GradoĊ„, P. A1 - Binczyk, F. A1 - Cwajna, J. A1 - Roskosz, S. PB - The Katowice Branch of the Polish Academy of Sciences DA - 2012 T1 - Evaluation of Metallurgical Quality of Master Heat IN-713C Nickel Alloy Ingots UR - http://www.journals.pan.pl/dlibra/publication/edition/87024 T2 - Archives of Foundry Engineering ER -