17:25 〜 17:45
[14E-T16-07] Study on Microstructure and Magnetic Properties of SmCo Permanent Magnets with Different Heat Treatment Conditions
キーワード：SmCo, Sloution Treatment, Isothermal Aging, TEM, Microstructure Analysis
Sm-Co Magnets are attracting attention especially in the military equipment and automobile market due to their high-temperature magnetic properties and coercivity. In Sm2Co17 magnets, the supersaturated phase is formed by solution treatment after the sintering. Then it undergoes two-step heat treatment process consisting of isothermal heat treatment at around 850℃ for about 20 hours, followed by annealing at around 400℃ for about 10 hours. By forming a cell structure through the formation of SmCo5 boundary phase covering the Sm2Co17 main phase, high coercivity can be achieved. In this study, we find the optimal process conditions through observing microstructures and magnetic properties with different heat treatment conditions including solution treatment, 1st isothermal aging and 2nd isothermal aging step. We investigate the correlation between magnetic properties and microstructure such as the formation of main phase, boundary phase and z-phase, continuity, and distribution of solute atoms.