Title :
Study of the effect of Zr-substitution on the HDDR characteristics of Nd-Fe-B-type alloys
Author_Institution :
Dept. of Mater. Sci. & Eng., Pukyong Nat. Univ., Pusan, South Korea
fDate :
9/1/1997 12:00:00 AM
Abstract :
Alloys with compositions based on Nd16Fe76-xB8Zrx (where x=0-2.0) have been studied to see the effect of Zr-substitution on the hydrogenation, disproportionation, desorption, recombination (HDDR) characteristic of the Nd-Fe-B-type alloys. The HDDR characteristics of the alloys were investigated by means of DTA, TPA and magnetic measurement. It has been found that a small substitution (0.1 at%) of Zr for Fe in the Nd-Fe-B-type alloy retards the disproportionation kinetics of the hydrogenated material. The desorption characteristic of the disproportionated materials has been found not to be affected significantly by the Zr-substitution. The Zr-substitution has been found to facilitate the recombination reaction. The peak coercivity of the HDDR treated material has been found to increase with increasing Zr-content. It has also been revealed that the Zr-substitution suppressed the degradation of the coercivity due to the excessive grain growth of the recombined grains on prolonged recombination
Keywords :
boron alloys; coercive force; desorption; ferromagnetic materials; grain growth; iron alloys; neodymium alloys; permanent magnets; powder metallurgy; thermal analysis; zirconium alloys; DTA; HDDR characteristics; Nd-Fe-B; Nd-Fe-B-type alloys; Nd16Fe74B8Zr2; Nd16Fe75B8Zr; Nd16Fe76-xB8Zrx; Nd16Fe76B8; TPA; Zr-content; Zr-substitution; coercivity; desorption characteristic; disproportionation kinetics; excessive grain growth; hydrogenated material; magnetic measurement; peak coercivity; prolonged recombination; recombination reaction; recombined grains; Absorption; Annealing; Hydrogen; Isothermal processes; Kinetic theory; Lead; Monitoring; Temperature; Zirconium;
Journal_Title :
Magnetics, IEEE Transactions on
