Abstract
Sufficient green strength can be attained for water atomized and annealed high speed steel powder with the M2 grade by use of conventional die pressing. In addition, this obtained green compact can be sintered to the full density by liquid-phase sintering. However, fine control of the sintering temperature is required for this type of eutectic sintering.
The high pressure compaction was tried to improve the sinterability on the solid-phase sintering. The two-step pressing method is applied to the high pressure compacting. High pressure up to 1470MPa can be attained by a special die assembly and apparatus. The sintered density reached to 7.4 g/cm3 with very little shrinkage in dimension by-0.8%. The radial crushing strength of sintered compacts increased in proportion to the compacting pressure.
These benefits in sinterabilty means that this is a more economic net shaping P/M process for wear-resistant machine parts.
