Texture development and coercivity enhancement in cast alnico 9 magnets

Authors

Wenyong Zhang, University of Nebraska - LincolnFollow
Shah Valloppilly, University of Nebraska-Lincoln
Xingzhong Li, University of Nebraska-LincolnFollow
Lanping Yue, University of Nebraska-Lincoln
Ralph Skomski, University of Nebraska-LincolnFollow
Iver Anderson, Iowa State University
Matthew Kramer, University of Nebraska - Lincoln
Wei Tang, University of Nebraska-Lincoln
Jeff Shield, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Date of this Version

12-27-2017

Citation

056215-2 Zhang et al. AIP Advances 8, 056215 (2018) Page 1-5

Comments

© 2017 Author(s).

Abstract

The effect of Y addition and magnetic field on texture and magnetic properties of arc-melted alnico 9 magnets has been investigated. Small additions of Y (1.5 wt.%) develop a (200) texture for the arc-melted alnico 9 magnet. Such a texture is hard to form in cast samples. To achieve this goal, we set up a high-field annealing system with a maximum operation temperature of 1250⁰ C. This system enabled annealing in a field of 45 kOe with subsequent draw annealing for the solutionized buttons; we have been able to substantially increase remanence ratio and coercivity, from 0.70 and 1200 Oe for the Y-free alnico 0 to 0.90 and 1400 Oe for the Y-doped alnico 9, respectively. A high energy product of 7.3 MGOe has been achieved for the fully heat-treated Y-doped alnico 9. The enhancement of coercvity is believed to arise from the introduction of magnetocrystalline anisotropy from 80 nm Y₂Co₁₇- type grains, which are exchange-coupled to the main-phase alnico rods.