This paper describes the influence of heat treatment on the microstructure and magnetic properties of MnSnCoN alloys. After homogenization at 950°C for 20 h in Ar, Mn82.5Sn10CO7.5 alloys were annealed at 900°C for 120 h in N2 and quenched to room temperature (first-annealing). The alloys were subsequently annealed at 400700° C for 5 h in N2 and quenched to room temperature (second-annealing). The coercivity of the alloys changed drastically by the second annealing. The samples subjected to second annealing at 500°C showed maximum coercivity of 1270kAm-1 and exhibited a fine two-phase microstructure. Wavelength Dispersive X-ray Spectrometer (WDS) and X-ray Diffraction (XRD) analyses revealed that the fine two-phase microstructure consists of β-Mn and perovskite-type (Mn4N-like) phases, as well as that the two phases emerged from the A phase during the second-annealing at 500°C.
- Heat treatment
- Manganesetincobalt nitrided alloy
- Two-phase microstructure