CuO-Al2O3/camphene 슬러리의 동결건조 공정에 의한Al2O3 입자분산 Cu 다공체 제조

Porous Cu with a dispersion of nanoscale Al2O3 particles is fabricated by freeze-drying CuO-Al2O3/camphene slurry and sintering. Camphene slurries with CuO-Al2O3 contents of 5 and 10 vol% are unidirectionally frozen at -30°C, and pores are generated in the frozen specimens by camphene sublimation during air drying. The green bodies are sintered for 1 h at 700°C and 800°C in H2 atmosphere. The sintered samples show large pores of 100 μm in average size aligned parallel to the camphene growth direction. The internal walls of the large pores feature relatively small pores of ~10 μm in size. The size of the large pores decreases with increasing CuO-Al2O3 content by the changing degree of powder rearrangement in the slurry. The size of the small pores decreases with increasing sintering temperature. Microstructural analysis reveals that 100-nm Al2O3 particles are homogeneously dispersed in the Cu matrix. These results suggest that a porous composite body with aligned large pores could be fabricated by a freeze-drying and H2 reducing process.