A FeNiMnC alloy with strain glass transition

Recent experimental and theoretical investigations suggested that doping sufficient point defects into a normal ferroelastic/martensitic alloy systems could lead to a frozen disordered state of local lattice strains (nanomartensite domains), thereby suppressing the long-range strain-ordering martensitic transition. In this study, we attempt to explore the possibility of developing novel ferrous Elinvar alloys by replacing nickel with carbon and manganese as dopant species. A nominal Fe₈₉Ni₅Mn_4.6C_1.4 alloy was prepared by argon arc melting, and XRD, DSC, DMA and TEM techniques were employed to characterize the strain glass transition signatures, such as invariance in average structure, frequency dispersion in dynamic mechanical properties (storage modulus and internal friction) and the formation of nanosized strain domains. It is indicated that doping of Ni, Mn and C suppresses γ→α long-range strain-ordering martensitic transformation in Fe₈₉Ni₅Mn_4.6C_1.4 alloy, generating randomly distributed nanosized domains by strain glass transition.