Warm Flow Compaction Forming of Complex Part by Using Binder-Treated Powder

Powder metallurgy process is a net-shape manufacturing technique that can eliminate or reduce machining time. It is economical and environmental friendly since no scrap is being produced and no high energy consuming process such as melting is involved. Unfortunately, conventional powder metallurgy is not capable of producing complex parts. However, a recently developed binder-treated warm compaction technique can overcome this problem by increasing the flowability of the mixed powder. In this study, by using a commercially available water-atomized iron powder, a cross-shaped part was prepared by warm compaction of a binder-treated iron-base powder at approximately 80 °C and then sintered at 1120 °C. Microstructure, mechanical property and shape consistency of the prepared part were examined. Results showed that parts with high density and high green strength can be obtained without significant shrinkage or expansion. The present paper demonstrated that the binder-treated warm compaction process can expand the capability of powder metallurgy techniques to produce complex parts.