Influence Of Alloy Elements On The Microstructure And Magnetic Properties Of SmCo/α-(Fe,Co) Nanocomposite Magnets

Nanocomposite permanent magnet materials is expected to become the next generation of permanent magnets,and nanocomposite SmCo / α-(Fe,Co)to meet the high temperature requirements was studied by researchers.Up to now,although some progresses have been obtained in the nanocomposite SmCo/α-(Fe,Co),there are still many scientific problems to be solved.In this paper,the influence of alloying elements Zr,Cu,Fe on the microstructure and magnetic properties of nanocomposite SmCo / α-(Fe,Co)was systematically analyzed by using X-ray diffraction(XRD)and vibrating sample magnetometer(VSM)techniques.The experimental method is that we melted the SmCo hard magnetic phase adding different alloying elements and mixed the soft magnetic phase by high energy ball milling to prepare amorphous precursor,and cold-pressed then annealed at different temperatures.Studies have shown that the soft phase content is 23 % in SmCo amorphous alloy precursor with no adding alloying elements.The phase transformation process is that amorphous crystal crystallize SmCo7 phase.The maximum energy product is 9.04 MGOe and coercivity is 4.24 kOe at 720 ℃ annealing.Zr can enhance the crystallization temperature of SmCo7 phase,and the grain size of soft phase can be refined effectively.The maximum energy product is 9.26 MGOe at 720℃ annealing.Cu can reduce the crystallization temperature of SmCo7 phase.The coercivity increases by 45 %,and the maximum energy product is 9.54 MGOe at 720 ℃ annealing.The addition of Cu and Zr increases the coercivity by 56 %,and the maximum energy product is 10.30 MGOe at 500 ℃ annealing.Their phase transformation process is the same as SmCo amorphous alloy with no adding alloying elements.The soft phase content in the precursor is 35 % with adding alloying element Fe,and the maximum energy product is 8.71 MGOe at 650 ℃ annealing.The soft phase content in the precursor is 32 % with adding alloying elements Fe and Zr,and the maximum energy product is 9.47 MGOe at 650 ℃ annealing.The soft phase content in the precursor is 40% with adding alloying elements Fe and Cu.The coercivity increases by 50 %,and the maximum energy product is 8.87 MGOe at 580 ℃ annealing.The simultaneous addition of Fe,Cu and Zr greatly improves the ability of hard phase amorphous formation during the milling process,and the soft phase content in the precursor is 37 %.The phase transformation process also has the precipitation of Sm-rich phase.The coercivity increases by 46 %,and the maximum energy product is 9.04 MGOe at 650 ℃ annealing.