Texture development and coercivity enhancement in cast alnico 9 magnets

Journal Article · Wed Dec 27 00:00:00 EST 2017 · AIP Advances

DOI:https://doi.org/10.1063/1.5007171· OSTI ID:1556932

Zhang, Wenyong ^[1]; Valloppilly, Shah  ^[1]; Li, Xingzhong ^[1]; Yue, Lanping  ^[1]; Skomski, Ralph ^[1]; Anderson, Iver  ^[2]; Kramer, Matthew ^[2]; Tang, Wei ^[2]; Shield, Jeff ^[1]; Sellmyer, David J. ^[1]

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1. Univ. of Nebraska, Lincoln, NE (United States)
2. Ames Lab., Ames, IA (United States)

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 1250 °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 9 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 coercivity 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.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: under Award ECCS: 1542182; AC02-07CH11358
• OSTI ID: 1556932
• Alternate ID(s): OSTI ID: 1414985
• Report Number(s): IS-J-9633
• Journal Information: AIP Advances, Vol. 8, Issue 5; ISSN 2158-3226
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE