Fabrication of Lotus-Type Porous NiAl and Ni3Al Intermetallic Compounds
Lotus-type porous NiAl and Ni3Al intermetallic compounds, possessing cylindrical pores aligned in the direction parallel to the solidification direction, were fabricated by using a unidirectional solidification technique in a pressurized hydrogen atmosphere of 2.5MPa. The porosity of lotus NiAl is 24.2 %, and the porosity of lotus Ni3Al is 3.2%; the porosity of the porous NiAl is larger than that of Ni3Al. This is because the solubility gap of hydrogen between liquid and solid phases of NiAl is larger than that of Ni3Al.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
T. Ide et al., "Fabrication of Lotus-Type Porous NiAl and Ni3Al Intermetallic Compounds", Solid State Phenomena, Vols. 124-126, pp. 1721-1724, 2007