Study On The Preparation Of Ni Membrane And Pd Membrane Supported On TiAl Intermetallic Alloy

The commercial membrane materials mainly include organic, ceramic and metal at present. Compared to organic membranes and ceramic membranes, metallic membranes offer better mechanical strength, operation at high pressures, resistance to cracking, ease of module fabrication and sealing. This paper investigated the preparation of porous nickel membrane and dense palladium membrane supported on TiAl intermetallic alloy.A composite MF membrane consisting of a nickel layer on a porous TiAl intermetallic compound substrate was prepared using sedimentation method and dip-coating method. For sedimentation method, influences of nickel content on the integrality of the membrane were investigated. The membrane thickness increased and the pore size decreased with increasing nickel content. For dip-coating method, the thickness was in direct proportion to the square root of dip-coating time from 30 s to 60 s and then decreased after 60 s. It was suitable to control dip-coating time 60 s. Influences of the sintering programs were investigated systemically. The optimized sintering temperature was 500℃. Ni/TiAl membrane with smooth surface and a relatively narrow pore size distribution was obtained by dip-coating. The membrane has an average pore size of 0.83μm, a thickness of about 30μm. The pure water flux of the membrane was about 6782 L·m-2·h-1and stable filtration flux for CaCO3 suspension was about 380 L·m-2·h-1. The membrane was put in NaOH solution to investigate the alkalescence resistance. After 41 days, the pore size and pure water flux were not changed, which indicated the alkalescence resistance of the membrane was good.Pd membranes supported on TiAl were prepared by electroless plating. The defect-free palladium membrane could be obtained after coating nickel powder and then abrading TiAl supports. It was discovered that the selectivity of the Pd membrane supported on Ni/TiAl sintering in air atmosphere decreased with increasing temperature. The failure of the Pd membrane resulted from reduction of the NiO by...