Multi-phase microstructures were observed in the psuedo-quaternary phase fi
eld of the 2-14-1 magnet materials Nd2Fe14B, Nd2Co14B, Dy2Fe14B, and Dy2Co1
4B. At equilibrium, (Nd1-yDyy)(2)(Fe1-xCox)(14)B had heretofore been widely
assumed to be single phase where 1 > x > 0 and 1 > y > 0. In this study, t
hree-phase microstructures were observed in (Nd1-yDyy)(2)(Fe1-xCox)(14)B wh
en x > 0.3 and y > 0.5. The Curie temperatures and peritectic decomposition
temperatures for Nd-2(Fe1-xCox)(14)B are reported for several values of x
in the range 1 > x > 0. (C) 2001 Published by Elsevier Science B,V.