Development of high performance Pr2(Fe, Co)14B/α-(Fe, Co)-type nanocomposite ribbons by Co/Ti/C substitution

Pr-lean and boron enriched Pr9Febal.CoxTiyB11-zCz (x=0, 10; y=0, 2.5 and 4; z=0-11) alloys have been employed in melt spinning to develop high coercivity and high magnetic energy product nanocomposite ribbons. Increase in C substitution in Co-free Pr9Febal.Ti2.5B11-zCz (z=0-11) ribbons degrades Br, iHc and (BH)max monotonically. However, in higher Ti content Pr9Febal.Ti4B11-zCz ribbons, a slight substitution of C for B (z=0.5-1) is beneficial in simultaneously improving the coercivity and magnetic energy product. Further substitution of 10 at.% Co for Fe may improve not only the magnetic properties but also the temperature coefficient of remanence and the temperature coefficient of coercivity, which are mainly the results of the enhanced magnetization of both magnetically soft and hard phases and the refined microstructure. Optimum magnetic properties of Br=10.0 kG, iHc =10.5 kOe (BH)max =20.2 MGOe and α =-0.092% 0C-1, β =-0.504% 0C-1 could be achieved in Pr9Fe66Co10Ti4B10C1 ribbons