A Comparative Study on Microstructure and Properties of Fe17Mn and Fe17Mn0.1C0.4Ti Damping Alloys under Different Annealing Processes

The microstructure and properties of Fe17Mn and Fe17Mn0.1C0.4Ti (i.e. FM and CTi) alloys were studied comparatively. Some fine TiC particles are precipitated within CTi alloy and the sizes of γ-austenite and ε-martensite phases are reduced by adding trace C and Ti. The γ → ε transformation temperature decreases while the content of ε phase increases with C and Ti additions. In addition, the CTi alloy possesses higher strain energy storage, lower stacking faults probability, more strong and weak pinning points, resulting in a lower damping capacity compared to FM alloy. Although CTi alloy exhibits lower damping capacity than FM alloy, the addition of C and Ti reduces the annealing temperature and time to achieve the optimal damping capacity. The additions of C and Ti significantly enhance the tensile strengths, with the highest values achieved for both alloys after annealing at 900°C for 1 h, reaching 699.5 MPa for FM alloy and 819.1 MPa for CTi alloy.