Development Of Metal Substrates For Gas Separation Membranes By Spark Plasma Sintering (SPS)

Metal supported ceramic membranes are of increasing interest for gas separation since they combine functionality with mechanical stability. Powder metallurgy is the preferred method for manufacturing of metal substrates for supporting the functional ceramic layers, e.g. with proton conducting properties. In the present work, spark plasma sintering (SPS) is introduced for the manufacturing of metal substrates with a stepwise gradient in porosity. The main purpose of the gradient was the combination of a densified edge enabling gas tight sealing of the membrane in a membrane reactor with a highly porous central part required for feeding of gases to the functional membrane layer. For proof of function, the substrates were coated with a proton conducting lanthanum tungsten (La6-xWO12-d) membrane by plasma spray - physical vapor deposition (PS-PVD). To withstand the harsh conditions in a membrane reactor, high temperature resistant NiCoCrAlY alloy was used as substrate material. Membrane characterization comprises microstructure investigation and phase analysis by X-ray diffraction.