Effect of withdrawal rate and zinc content on pore structure and morphology of lotus-type porous Cu–Zn alloys fabricated using continuous casting

A continuous casting technique was developed to fabricate lotus-type porous alloys. This type of porous Cu–Zn (2, 6, and 10 wt.%) alloy was successfully fabricated by using the continuous casting technique under a hydrogen gas pressure of 0.6 MPa at various withdrawal rates. The influences of processing parameters on the pore structure and morphology were investigated. For the porous Cu-2Zn alloys, an increased withdrawal rate will result in slightly increased porosity, but a decreased average pore diameter. The pore morphology becomes more and more inhomogeneous with increasing Zn content, and the porosity tends to firstly decrease and subsequently increase. Such tendencies are correlated with the Zn content and corresponding width of the mushy zone.