Achieving superior cryogenic tensile properties in a Ti-doped (Fe40Mn40Co10Cr10)96.7C3.3 high-entropy alloy by recovering deformation twinning

• DOI: 10.1016/j.msea.2021.140927
• Publication Date: 2021-02-15T12:47:58Z
• Authors: K. Tang; Y.K. Wu; R. Wei; L.B. Chen; S. Lu; Y.L. Qi; F. Jiang; J. Sun
• Keywords: Deformation mechanism; Titanium alloy; Elongation

Abstract A minor Ti-doped (Fe40Mn40Co10Cr10)96.7C3.3 high-entropy alloy presents a higher yield strength and a littler lower elongation than the un-doped one at room temperature. And more interestingly, superior cryogenic temperature (77 K) tensile properties: yield strength of ~1 GPa, ultimate tensile strength of ~1.5 GPa, and elongation of ~52% are achieved in this alloy. The high yield strength is attributed to the improved strengthening effect by the grain boundary and nano-sized TiC precipitation and the better ductility at cryogenic temperature is ascribed to the recovery of deformation twinning by titanium addition. It is proposed that the critical twinning stress of C-contained alloy is temperature dependent, which is related with the unbalanced pinning effect assisted twinning mechanism due to carbon diffusion.