On the mechanical response and microstructure evolution of NiCoCr single crystalline medium entropy alloys Academic Article uri icon

abstract

  • © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Unusual strain hardening response and ductility of NiCoCr equiatomic alloy were investigated through microstructural analysis of [111], [110] and [123] single crystals deformed under tension. Nano-twinning prevailed at, as early as, 4% strain along the [110] orientation, providing a steady work hardening, and thereby a significant ductility. While single slip dominated in the [123] orientation at the early stages of deformation, multiple slip and nanotwinning was prominent in the [111] orientation. Significant dislocation storage capability and resistance to necking due to nanotwinning provided unprecedented ductility to NiCoCr medium entropy alloys, making it superior than quinary variants, and conventional low and medium stacking fault energy steels. IMPACT STATEMENT: A comparison of the current results on the ternary medium entropy alloy single crystals and those previously reported on the quinary and quaternary fcc equiatomic alloys demonstrates that a higher configurational entropy does not necessarily warrant improved mechanical properties.

author list (cited authors)

  • Uzer, B., Picak, S., Liu, J., Jozaghi, T., Canadinc, D., Karaman, I., Chumlyakov, Y. I., & Kireeva, I.

citation count

  • 25

publication date

  • August 2018