Abstract: A method of joining at least two sintered bodies to form a composite structure, includes: providing a joint material between joining surfaces of first and second sintered bodies; applying pressure from 1 kP to less than 5 MPa to provide an assembly; heating the assembly to a conforming temperature sufficient to allow the joint material to conform to the joining surfaces; and further heating the assembly to a joining temperature below a minimum sintering temperature of the first and second sintered bodies. The joint material includes organic component(s) and ceramic particles. The ceramic particles constitute 40-75 vol. % of the joint material, and include at least one element of the first and/or second sintered bodies. Composite structures produced by the method are also disclosed.

Abstract: Method of making an electrochemical device for the recovery of oxygen from an oxygen-containing feed gas comprising (a) preparing a green electrochemical device by assembling a green electrolyte layer, a green anode layer in contact with the green electrolyte layer, a green cathode layer in contact with the green electrolyte layer, a green anode-side gas collection interconnect layer in contact with the green anode layer, and a green cathode-side feed gas distribution interconnect layer in contact with the green cathode layer; and (b) sintering-the green electrochemical device by heating to yield a sintered electrochemical device comprising a plurality of sintered layers including a sintered anode-side gas collection interconnect layer in contact with the anode layer and adapted to collect oxygen permeate gas, wherein each sintered layer is bonded to an adjacent sintered layer during sintering.