抄録
The swelling of cylindrical compacts, 10 mm(d)×10 mm (h) in size, was measured with a micrometer during each production process; after pressing at 2-8 t/cm2 (196-784 MPa), after dewaxing at 500°C (773K) for 30 min, and after sintering at 900°C (1173 K) for 5-180 min.
Compacts pressed under higher pressures (588-784 MPa) swelled during sintering, while those pressed under lower pressures (196-392 MPa) shrank. Both the swelling and the shrinkage of compacts pressed with die-wall lubrication and sintered in cracked ammonia gas were larger than those of compacts pressed with powder lubrication or sintered in argon gas. Dimensional change during sintering was larger in swelling or smaller in shrinkage, in the pressing direction than in the lateral direction.
The sintering time for the swelling of electrolytic copper powder compacts in argon gas was longer than that of the compacts sintered in cracked ammonia gas or of the compacts made from atomized copper powder.
