Alloys, magnetic materials, bonded magnets and methods for producing the same

A method for preparing an alloy ribbon with composition comprising Formula (I):

• RE-Fe-M-B Formula (I)
• wherein:
• RE is one or more rare earth metals selected from the group consisting of lanthanum (La), cerium (Ce), neodymium (Nd), praseodymium (Pr), yttrium (Y), gadolinium (Gd), terbium (Tb), dysoprium (Dy), holmium (Ho), and ytterbium (Yb);
• Fe is iron;
• M is absent or one or more metals selected from the group consisting of zirconium (Zr), niobium (Nb), molybdenum (Mo), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), hafnium (Hf), tantalum (Ta), tungsten (W), cobalt (Co), copper (Cu), gallium (Ga) and aluminum (Al);
• and
• B is boron,
• wherein:
• the alloy comprises at least 98 vol % crystalline RE2Fe14B phase;
• the average crystal grain size of the RE2Fe14B phase is in the range of 20 nm to 40 nm;
• the alloy is an alloy ribbon having a width measured from a left edge to a center portion to a right edge, the center portion comprising from about 0.5% to about 20% of the width on either side of a center line of the alloy ribbon, the left and right edges each comprising up to 10% of the width of the alloy ribbon from their respective edges, and the average crystal RE2Fe14B grain size difference between the center portion, and left and right edges of said alloy ribbon is less than 20%;
• comprising the steps of:
• (i) ejecting a melt of an alloy with composition of Formula (I) onto a rotating wheel at a mass flow rate in the range of 0.2 kg/min to 1.0 kg/min, wherein the ejection temperature is in the range of 1400° C. to 1600° C., and wherein the wheel is rotating at a speed in the range of 20 m/s to 45 m/s;
• and
• (ii) quenching the melt using the rotating wheel to obtain said alloy ribbon.