Effect of casting temperature on porous structure of lotus-type porous copper

Lotus-type porous copper was fabricated using unidirectional solidification method by only changing casting temperature. Porous structure of the lotus-type porous copper was quantitatively characterized and analyzed. Effect of casting temperature on the porous structure was investigated and its mechanism was discussed. The results showed that casting temperature had little effect on porosity of the lotus-type porous copper at the temperature range of 1120-1180, i.e., the porosity was only increased by 2.7% at the above temperature range. Casting temperature had an obvious effect on the porous morphology and structure of the lotus-type porous copper. When casting temperature was raised, both the size of pore and thickness of pore-free zone decreased, and both the number and uniformity of pore increased. The above results were mainly ascribed to the solubility of gas in molten metal, the nucleation and growth mode of pore, and the growth mode of pore-free zone.