Superior damping capacity of a C-containing FCC medium-entropy alloy

Construction machinery noise not only affects its service life, but also brings hazards to people's physical and mental health. Achieving a high and stable internal friction characteristic to eliminate noise and mechanical vibrations is always the desired goal in the design of damping alloys. In the study, we present a C-containing FeMn -Cr -Ni medium entropy alloy that exhibits a superior damping capacity with an internal friction peak value of 0.083. The Finkelstein-Rosin relaxation peak appears at 550 K in the internal friction spectrum, which is attributed to the reorientation of C-C pairs and C substitutional atom pairs under stress, with the diffusion activation energy are 155.172 kJ & sdot;mol-1 and 166.711 kJ & sdot;mol-1, respectively. The relaxation of Finkelstein-Rosin peak enhances the damping capacity of the alloy, which provides an effective method for regulating the damping properties of medium entropy alloys.