2009 Volume 50 Issue 12 Pages 2891-2896
The formation mechanism of microchannels with Fe-Cu alloy lining layers in iron bodies produced by a powder-metallurgical microchanneling process has been investigated. Copper wire was used as a sacrificial core that gives the shape of the microchannel and supplies the alloying element for the lining layer. An iron powder compact containing the sacrificial core was heated and sintered at temperatures between the melting points of copper and iron. Quenching experiments showed that the microchannel was produced just after melting of copper. In a quenched specimen with a newly-formed microchannel, fine copper-rich regions were observed between the iron powder particles in the lining layer. These results established that infiltration of molten copper into the iron powder is the dominant mechanism for the Fe-Cu microchanneling process. It was also found that the liquid copper infiltrated via preferential flow pathways between the iron powder particles.