Studium vybraných termofyzikálních a termodynamických vlastností slitin na bázi Ni

Abstract

The aircraft industry often uses nickel based super-alloys for blades of the jet-turbine engines. It is so because this material must satisfy numerous extreme requirements, such as e.g. heat-resistance at high temperatures, resistance to fatigue damage, etc. Used materials are usually alloyed in complex manner and their structure is very complicated. This work deals with an experimental investigation of phase transformation temperatures and phase transformation latent heats of selected nickel based super-alloys (IN 713LC, IN 738LC, IN 792-5A) with use of Differential Thermal Analysis (DTA method). Samples taken from as-received state of superalloys were heated with controlled ramp rates (1, 5, 10, 20 and 50°C/min) and immediately after melting they were cooled with the same controlled ramp rate with the help of the laboratory experimental system SETARAM Setsys 18TM. Moreover, the transformation temperatures at zero heating/cooling rate were determined. Phase transformation temperatures and phase transformation latent heats were compared with results presented in literature. The samples before and after DTA - analysis were also subjected to the phase analysis with use of scanning electron microscopy.