Chemical Partitioning During Crystallization and its Effect on the Microstructure and Magnetic Behavior of Modified Ndâ•fiFeâ•fiB Permanent Magnets
نویسندگان
چکیده
In this paper, the effect of alloy composition on the microstructural development of devitrified Nd–Fe–B-based alloys is investigated. While crystallization of simple ternary Nd2Fe14B resulted in a highly variable microstructure and relatively poor demagnetization behavior, alloying additions, notably Ti and C, were found to significantly refine and homogenize the crystallized microstructure. High spatial resolution energy dispersive X-ray spectroscopy revealed that partitioning to the grain boundaries led to the grain refinement by slowing interface kinetics. The more homogeneous grain structure resulted in improved demagnetization behavior, but segregating elements isolated grains and limited intergranular exchange coupling. r 2002 Published by Elsevier Science B.V. PACS: 75.50.Ww; 75.20.En; 75.30.Et
منابع مشابه
Structure and magnetic properties of N-containing Ndâ•fiFeâ•fiB alloys prepared by mechanical alloying
متن کامل
The Effect of Heat Treatment on Microstructure and Magnetic Properties of Nd17Fe76.5B5Cu1.5 Type Sintered Magnets
The effects of high temperature homogenization and low temperature annealing treatments on the microstructure and magnetic properties of sintered magnets of an Nd17Fe76.5B5Cu1.5 type alloy have been investigated. The microstructure of the as-cast alloy, consisted of three phases including a Nd2Fe14B1 (2:14:1- type) matrix phase Cu-containing Nd-rich Phase and Free α-iron. The as-sintered magnet...
متن کاملThe Effect of Heat Treatment on Microstructure and Magnetic Properties of Nd17Fe76.5B5Cu1.5 Type Sintered Magnets
The effects of high temperature homogenization and low temperature annealing treatments on the microstructure and magnetic properties of sintered magnets of an Nd17Fe76.5B5Cu1.5 type alloy have been investigated. The microstructure of the as-cast alloy, consisted of three phases including a Nd2Fe14B1 (2:14:1- type) matrix phase Cu-containing Nd-rich Phase and Free α-iron. The as-sintered magnet...
متن کاملEffect of Post-Sintering Annealing Treatment on Magnetic Properties of Some Nd Fe b Based Magnets
Effects of post-sintering annealing treatment between 300 and 1000ºC for up to 8 hrs time periods followed by either furnace cooling (FC) or air-cooling (AC) on the hard magnetic properties of some Nd-Fe-B based sintered magnets was investigated. It was shown that the intrinsic coercivity (Hci), second quadrant demagnetization loop shape and thus the energy density (BH)max varied considerably a...
متن کاملINFLUENCE OF HEATING RATE ON MICROSTRUCTURE AND MAGNETIC PROPERTIES OF Fe3B/Nd2Fe14B NANOCOMPOSITE MAGNETS
The nanocomposite magnet, which is composed of exchange coupled nanocrystalline soft (Fe3B, α-Fe) and hard (Nd2Fe14B) magnetic phases, was first reported by Coehoorn et al. [1], and the theoretical basis of it was reported by Kneller and Hawig [2]. Nd-Fe-B based nanocomposite magnet has attracted considerable research interest due to its excellent magnetic properties with relatively low amount ...
متن کامل