Characterization of high entropy alloy CrMnFeCoNi over a wide temperature rangeWednesday (26.09.2018) 10:45 - 11:00 S1/01 - A5 Part of:
The equiatomic single phase high entropy alloy CrMnFeCoNi (20 at.% of each element) also known as Cantor alloy is an ideal candidate for the study of solid solution hardening in a statistically distributed crystal lattice. Cantor alloy shows extraordinary mechanical properties. To investigate the single-phase Cantor alloy in more detail the focus lies on the entropy affecting mechanical properties. An important part of the characterization exhibits the measurement of the specific heat capacity (cp) of the Cantor alloy over a temperature from -170 °C up to the melting point. This was realized by using two Netzsch DSC instruments. The entropy can subsequent determined by integration. Using an arc-melting furnace, the master alloys were melted under argon in the first step. Then the pre-alloyed buttons were casted as a single-crystal (SX) as well as a polycrystalline material by induction casting under argon for further characterization. Because of the vaporization of Mn, an optimal input of Mn was found at 21-22 at.%. For the mechanical testing of the Cantor miniature specimens are prepared by electrical discharge machining (EDM) after a heat treatment process under vacuum. The tensor of elastic properties were determined by using ultrasound resonant spectroscopy (geometry 4x5x6 mm3) from room temperature up to 1300 °C. Whereas tensile tests (geometry 27x7x1 mm3) were carried out close to liquid helium temperature at -269 °C up to 1300 °C. Furthermore, the alloys were analyzed respective their microstructure and composition by SEM and EDS as well as µ-XRF.