Effects of W substitution on the magnetic properties, phase evolution and microstructure of rapidly quenched Co sub(80)Zr sub(18)B sub(2 ) alloy

• Published in: Journal of magnetism and magnetic materials Vol. 368; pp. 116 - 120
• Main Authors: Hou, Zhipeng, Yang, Chongli, Xu, Shifeng, Zhang, Jinbao, Liu, Dan, Su, Feng, Wang, Wenquan
• Format: Journal Article
• Language: English
• Published: 01-01-2014
• Subjects: Coercive force; Evolution; Heat treatment; Magnetic properties; Melt spinning; Microstructure; Ribbons; Scanning electron microscopy
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2014.05.024

The effects of a partial substitution of W for Zr on the magnetic properties, phase evolution, and microstructure of Co sub(80)Zr sub(18-x)W sub(x)B sub(2) (x=0, 1, 2 and 3) melt-spun ribbons are investigated in this paper. For the as-spun samples, the optimal magnetic properties of sub(i)H sub(C)= 6.6 kOe and (BH) sub(max)=4. 5 MGOe are achieved in the C0 sub(80)Zr sub(16)W sub(2 )B sub(2). Thermomagnetic analysis (TMA) and x-ray diffraction (XRD) results suggest that the as-spun Co sub(80)Zr sub(18-x)W sub(x)B sub(2) mainly comprises of hard magnetic phase. Scanning electron microscope (SEM) results indicate that W addition refines the microstructure, which results in an increase in the intergrain exchange interaction. The effects of heat treatment on the magnetic properties of as-spun Co sub(80)Zr sub(18-x)W sub(x)B sub(2) (x=0,1,2 and 3) are also studied. The maximum sub(i)H sub(c) of 7.3 kOe with a (BH) sub(max) of 3.8 MGOe is obtained in the Co sub(80)Zr sub(16)W sub(2 )B sub(2) after a heat treatment at 550 [degrees]C. The origin of coercivity enhancement in Co sub(80)Zr sub(16)W sub(2 )B sub(2) is ascribed to the increase in magnetocrystalline anisotropy field (H sub(a)) of hard magnetic phase.