Temperature dependent load partitioning and slip mode transition in a eutectic AlCoCrFeNi2.1 high entropy alloy
Nitesh Raj Jaladurgam, Adrianna Łozinko, Sheng Guo, Tung-Lik Lee, Magnus Hörnqvist Colliander
Abstract
Eutectic high entropy alloys are gaining increasing attention due to their excellent castability and combination of strength and ductility in the as-cast state. However, the detailed behavior of the nano-scale lamellar microstructure during deformation, and in particular the interaction between the phases, is not well understood. Here we use in-situ neutron diffraction during tensile testing over a wide temperature range (77–673 K) to obtain new insights into the temperature dependent mechanical interactions between and within phases during initial plastic deformation of an AlCoCrFeNi2.1 eutectic high entropy alloy. The load was transferred from the L12 to the B2 phase during the yielding process, and the changing load distribution within the L12 phase with increasing temperature strongly suggests that <110>{001} cube slip is activated at room temperature and above. This points towards alloying design for delayed octahedral-to-cube slip transition as a possible strategy for increasing the high temperature strength of material.