Fabrication of a graded pore-sized porous FeAl intermetallic membrane

Abstract

Micro-porous FeAl membranes were prepared directly onto a macro-porous FeAl support through brushing and reactive synthesis using Fe and Al elemental powders with different particle sizes. X-ray diffraction, scanning electron microscope and pore structure testing were used to study the phase composition, interfacial microstructure and pore structure of the resulting graded pore-sized FeAl membrane. The effects of membrane thickness on permeability and maximum pore size were also investigated. Results showed that a metallurgically strong joint is formed between the membrane and support and that no cracks and defects may be found on the interface due to the elemental reactions, penetrating of coated powders into the pores of the support and the match of the thermal expansion coefficients between membrane and support. Membrane permeability decreased from 84.2 to 38.5 m 3 m −2 kPa −1 h −1 and the maximum pore size of about 2.5 μm showed a slight change as the membrane thickness increased from 135.5 to 299.1 μm.

Micro-/Nano-Dual-Scale Porous Composite Membranes for the Separation of Nanopollutants from Water

“…Porous filtration membrane has potential applications in gas/solid and liquid/solid purification, due to its unique features of homogeneous mesopore, tunable pore size, and large surface area. − Recently, much research had been carried out on various porous filtration membranes for protection of ecology and environment. − Among numerous filtration membranes, porous ceramic materials show disadvantages such as severe brittleness and high cost, while porous metallic materials have negative aspects in corrosion protection and oxidation resistance over 600 °C . Combining the advantages of ceramics and metals, TiAl-based alloy filtration membranes appeared to possess good mechanical properties, outstanding corrosion, and high oxidation resistance over 600 °C. , However, the insufficient filtration efficiency of the TiAl-based porous alloys, as mainly depends on the minimum aperture size, − greatly limits their practical application in nanopollutant/water separation. It should be highly attractive and potential for improving filtration capabilities of TiAl-based alloys through changing the minimum aperture size without decreasing other pore parameters.…”