tailieunhanh - Investigation of fabrication of Co-Zr based rare earth free hard magnetic alloys by melt spinning method

Their structure and magnetic properties were investigated by X-ray diffraction (XRD) and a pulsed field magnetometer (PFM), respectively. The results of the XRD analysis showed that two soft magnetic phases, namely Co and Co23Zr6, coexist with a Co5Zr hard magnetic phase in the alloy ribbons. | Vietnam Journal of Science and Technology 56 (1A) (2018) 14-24 INVESTIGATION OF FABRICATION OF Co-Zr BASED RARE EARTH-FREE HARD MAGNETIC ALLOYS BY MELT-SPINNING METHOD Nguyen Van Duong1, 2, *, Nguyen Mau Lam1, Duong Dinh Thang1, Nguyen Huy Ngoc3, Pham Thi Thanh2, 4, Nguyen Hai Yen2, 4, Do Bang4, Luu Tien Hung5, Nguyen Huy Dan2, 4 1 Hanoi Pedagogical University No 2, No 32 Nguyen Van Linh, Phuc Yen, Vinh Phuc, Viet Nam 2 Graduate University of Science and Technology, VAST, No 18 Hoang Quoc Viet, Cau Giay, Ha Noi, Viet Nam 3 VNU University of Engineering and Technology, No 144 Xuan Thuy, Cau Giay, Ha Noi, Viet Nam 4 Institute of Materials Science, VAST, No 18 Hoang Quoc Viet, Cau Giay, Ha Noi, Viet Nam 5 Nghean College of Education, No 389, Le Viet Thuat, Vinh, Nghe An, Viet Nam * Email: duongnvsp2@ Received: 15 August 2017; Accepted for publication: 5 February 2018 ABSTRACT Co-Zr based alloy has attracted much interest of potential to replace the rare earthcontaining hard magnetic materials due to its high coercivity. In this study, we investigated the effects of subtituting elements of M (Ti, Si and Nb) and annealing temperature on the structure and magnetic properties of Co79-xZr18+x-yMyB3 alloy ribbons (x = 0 - 2, y = 0 - 4). The alloy ribbons with a thickness of 20 µm were prepared by melt-spinning method with a rolling speed of 40 ms-1. A part of the melt-spun ribbons was annealed at different temperatures from 550 to 800 oC for various durations from 2 to 15 minutes. Their structure and magnetic properties were investigated by X-ray diffraction (XRD) and a pulsed field magnetometer (PFM), respectively. The results of the XRD analysis showed that two soft magnetic phases, namely Co and Co23Zr6, coexist with a Co5Zr hard magnetic phase in the alloy ribbons. The fraction of these phases was changed with both the concentration of the subtituting elements and annealing process. Hard magnetic properties of the alloy ribbons can be strengthened .