Microstructure of aged (Co,Cu,Fe)7Sm magnets

1977/03/01 by J. D. Livingston, D. L. Martin, Douglas L. Martin · 8 citations
Materials Science · Physics and Astronomy · #Magnetic Properties of Alloys #Magnetic Properties and Applications #Magnetic properties of thin films

paper · doi:10.1063/1.323729

Abstract

The microstructure of (Co,Cu,Fe)7Sm magnets has been characterized at various states of aging by transmission electron microscopy. At peak magnet properties, the magnet consists of cells of 17 : 2 phase about 500 Å in diameter, separated by a thin continuous fully coherent 5 : 1 boundary phase. This structure evolved by precipitation of ordered 17 : 2 particles from a disordered 5 : 1 matrix, and coarsens with aging until full coherence is lost and the cellular structure breaks up. The overaged alloy consists of semicoherent 5 : 1 particles in a 17 : 2 matrix, with a single set of interface dislocations accommodating the lattice mismatch. The effect of these various microstructural changes on domain-wall pinning and coercivity is discussed.

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• Local Phase Segregation Induced by Ion Milling in 2:17-Type Sm-Co Based Magnets. [europepmc]
• Identifying grain boundary and intragranular pinning centres in Sm 2 (Co,Fe,Cu,Zr) 17 permanent magnets to guide performance optimisation. [europepmc]

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