Sintering

Where it comes up

• Powdered metalNet-shape gears, bushings, and structural parts pressed from metal powder and sintered, with little or no machining.

Related terms

Green part

A green part is a powder metal part after compaction and before sintering. It holds its shape but has low strength, about like chalk, so it must be handled carefully. Green density, typically 6.4–7.2 g/cm³ for iron-based parts, sets final strength after sintering.

Compaction

Compaction is the powder metal step where metal powder is pressed in a rigid die, typically at 30–60 tons per square inch (415–830 MPa), to form a green part. Compaction pressure sets green density, which drives final strength. Part height and press tonnage limit what can be compacted.

Infiltration

Infiltration is a powder metal process where molten copper is drawn into the pores of a sintered steel part by capillary action. It raises density, strength, and impact toughness and can seal parts for pressure tightness. Copper-infiltrated steels carry the MPIF FX material designation.