Heat the appropriate amounts of the component metals (ie, iron, neodymium and boron) in a vacuum to prevent any reaction between air and the melting materials that might contaminate the alloy. Allow the alloy to cool and solidify.
Grind the alloy into a fine powder using a ball mill.
Press the powdered metal in a mold of the same dimensions as the finished permanent magnet. Use hydraulic or mechanical rams to apply pressures between 70 and 100 MPa to compress the powder into within 0.32 centimeters of its final intended thickness.
Remove the compressed metal from the mold and place it in the oven. Sinter the metal to transform it into fused, solid pieces through a three-stage process. First, heat the compressed material at a low temperature to drive off any moisture. Next, raise the temperature to 70 to 90 percent of the melting point of the alloy, and hold it there for several hours to several days. Finally, cool the material down in step-by-step temperature increments.
Anneal the metal through a controlled heating and cooling process in a large oven to strengthen the material and remove residual stresses.
Magnetize the material by placing it between the poles of a powerful electromagnet for several hours.