Title :
Magnetic hardening of Cr-/W-added NdDyFeCoB sintered magnets
Author :
Lin, Cheng-Hao ; Chin, T.S. ; Huang, Y.H. ; Yau, J.M. ; Cheng, K.H. ; chu, T.Y.
Author_Institution :
Dept. of Mater. Sci. & Eng., Tsing Hua Univ., Hsinchu, Taiwan
fDate :
11/1/1993 12:00:00 AM
Abstract :
The addition of 2 at.% Cr or W into a sintered (Nd,Dy)-Fe,Co)-B alloy is very effective in improving room temperature coercivity and thermal stability. The W-containing alloy shows twice the coercivity value of that of W-free alloy at temperatures higher than 100°C. Both W and Cr alloying greatly improve the high temperature stability. There exists a WFeB precipitate phase in the W-containing alloy. The WFeB phase is platelet with its long axis parallel to the c-axis of the 2-14-1 phase. The domain wall pinning at the precipitate phase, as evidenced by the Lorentz microscopy, is the cause of enhanced coercivity of this alloy, particularly at high temperatures
Keywords :
alloying additions; boron alloys; chromium alloys; cobalt alloys; coercive force; dysprosium alloys; ferromagnetic properties of substances; iron alloys; magnetic domain walls; neodymium alloys; optical microscopy; permanent magnets; precipitation; tungsten alloys; 100 degC; 2-14-1 phase; 20 degC; Cr alloying; Lorentz microscopy; NdDyFeCoB sintered magnets; NdDyFeCoBCr; NdDyFeCoBW; W-containing alloy; WFeB precipitate phase; domain wall pinning; high temperature stability; magnetic hardening; platelet; room temperature coercivity; thermal stability; Alloying; Chromium; Coercive force; Iron; Magnetic field measurement; Magnetic properties; Magnets; Niobium; Temperature; Thermal stability;
Journal_Title :
Magnetics, IEEE Transactions on
