Magnetic-field Orientation Press

Selection criteria

Alignment field strength (≥ 1.5 T), pressing force, glove-box oxygen level.

Supply chain

Magnetic-field orientation presses are mostly built in China and Japan for the magnet industry. Alignment field strength and glove-box atmosphere decide remanence; it is a good question to ask when auditing a magnet supplier.

Buyer FAQ

Why does the alignment field need to be at least 1.5 T?

Remanence rises with the degree of alignment, and weak fields leave particles partly misaligned, costing Br that later steps cannot recover. DC electromagnet presses typically provide about 1.5–2 T across the die cavity; pulsed fields can be higher. Ask for field measured in the cavity at production gap, not the coil's rated value.

Transverse or axial pressing?

In transverse pressing the field is perpendicular to the pressing direction, which disturbs alignment less and typically gives a few percent higher Br. Axial pressing, with field parallel to pressing, is used for rings and thin parts magnetised through the thickness. For high-grade blocks, ask the supplier which method is used.

What atmosphere and green-density controls matter?

Modern presses work inside a nitrogen glove box, with oxygen commonly held below a few hundred ppm and lower on high-coercivity lines. Green density is typically about 3.5–4.5 g/cm³, roughly half of the sintered value, and must be uniform to avoid cracking and distortion during sintering. Check that press force and fill weight are logged per pressing.

Where it is used