Ni-GDC microtubular cermets

Ni-GDC cermet tubes (~ 3 mm inside diameter, 0.3–0.4 mm wall thickness and ∼ 100 mm in length) with different amounts of porosity have been prepared by sintering of NiO-Ce0.9Gd0.1O1.95 (NiO-GDC) nanopowders and further reduction. The NiO-GDC nanopowders were synthesized by chemical route and the different pore density was obtained by modifying the processing conditions (calcining and adjustment of carbonous remains). cermets were obtained from the sintered NiO-GDC composites using reduction treatment at 700 °C for 3 h in reducing atmosphere (5 vol.% H2–95 vol.% Ar). After the reduction process, tubes with 25–32% porosity were obtained. Gas permeability and Hg porosimetry studies were used to evaluate permeability, pore distribution and pore density. Electrical conductivity studies of the cermets were also performed.