2015 年 40 巻 3 号 p. 261-265
Open-cell nickel aluminide (Ni-Al) intermetallics foams have attracted much attention in industries at which high temperature and severe environment are concerned, due to their good physical and chemical properties. A combination of different pore structures and morphologies in a single monolithic matrix can extend the properties of a material from which a wide range of applications can be applied. In the present study, open-cell Ni-Al intermetallic foams with hierarchical porosities have been developed through a sintering and dissolution process (SDP) and reactive synthesis techniques. The carbamide particles of various contents were used as a space holder material to create macropores in the foams. Micropores were formed as the result of to the formation of initial fine pores between the powders in the compacts, the volatilization of gases evolved during reactive sintering and different diffusion coefficients between Ni and Al. After sintering, only Ni3Al is present in the matrix.