Hf—Co—B alloys as permanent magnet materials
An alloy composition is composed essentially of Hf 2-X Zr X Co 11 B Y , wherein 0<X<2 and 0<Y≦1.5. Moreover, an alloy composition is composed essentially of ferromagnetic Hf 2-X Zr X Co 11 B Y , wherein 0≦X<2 and 0<Y≦1.5, and has a nanoscale crystalline structure comprising at least one non-equilibrium phase. The alloys can be melt-spun with in-situ and/or ex-situ annealing to produce the nanoscale crystalline structure.
1. A melt-spun, annealed alloy composition consisting essentially of melt-spun, annealed ferromagnetic Hf 2-X Zr X Co 11 B Y , wherein 0≦X<2 and 0<Y≦1.5, said melt-spun, annealed alloy composition having a nanoscale crystalline structure comprising at least one non-equilibrium phase.
2. A melt-spun, annealed alloy composition in accordance with claim 1 wherein X=0.
3. A melt-spun, annealed alloy composition in accordance with claim 1 wherein X>0.
4. A melt-spun, annealed alloy composition in accordance with claim 1 wherein said melt-spun, annealed alloy composition is ferromagnetic at room temperature and has a saturation magnetic moment of at least 50 emu/g.
5. A melt-spun, annealed alloy composition in accordance with claim 4 wherein said magnetic moment of at least 50 emu/g is persistent to a temperature of at least 100° C.
6. A method of making the melt-spun, annealed alloy of claim 1 comprising the steps of:
a. Forming an essentially, macroscopically homogeneous alloy consisting essentially of H 2-X Zr X Co 11 B Y , wherein 0≦X<2 and 0<Y≦1.5;
b. melt-spinning the alloy to form a ribbon having at least one microstructure selected from the group consisting of an amorphous phase and a nanoscale crystalline phase;
c. annealing the melt-spun alloy ex-situ to form a nanoscale crystalline structure therein.
7. A method of making a magnetic alloy in accordance with claim 6 wherein O<X<2.
8. A method of making a magnetic alloy in accordance with claim 6 wherein said annealing step is carried out within a magnetic field of least 1 Tesla to form an at least partially anisotropic microstructure therein.
9. A method of making the melt-spun, annealed alloy of claim 1 comprising the steps of:
a. Forming an essentially, macroscopically homogeneous alloy consisting essentially of H 2-X Zr X Co 11 B Y , wherein 0≦X<2 and 0<Y≦1.5;
b. melt-spinning and in-situ annealing the alloy to form a melt-spun alloy having a nanoscale crystalline structure therein.
10. A method of making a magnetic alloy in accordance with claim 9 wherein 0<X<2.
11. A method of making a magnetic alloy in accordance with claim 9 further comprising an annealing step comprising annealing the melt-spun alloy within a magnetic field of least 1 Tesla to form an at least partially anisotropic microstructure therein.