Spark Plasma Sintering Behaviors of M-type Barium Hexaferrite Nano Powders

A magnetic powder, M-type barium hexaferrite (BaFe12O19), was consolidated with the spark plasma sinteringprocess. Three different holding temperatures, 850oC, 875oC and 900oC were applied to the spark plasma sinteringprocess with the same holding times, heating rates and compaction pressure of 30 MPa. The relative density was measuredsimultaneously with spark plasma sintering and the convergent relative density after cooling was found to be proportionalto the holding temperature. The full relative density was obtained at 900oC and the total sintering time wasonly 33.3 min, which was much less than the conventional furnace sintering method. The higher holding temperaturealso led to the higher saturation magnetic moment (σs) and the higher coercivity (Hc) in the vibrating sample magnetometermeasurement. The saturation magnetic moment (σs) and the coercivity (Hc) obtained at 900oC were 56.3 emu/g and541.5 Oe for each.