A comparative study has been carried out on the effects of pore-forming agents on the microstructural characteristics and properties including porosity, microstructures, linear sintering shrinkage and mechanical strength of NiO/yttria stabilized zirconia (YSZ). Different pore-forming agents (soluble starch, graphite and activated carbon) were incorporated into NiO/YSZ at various mass mixing ratios (5%, 10% and 15%). The experimental results show that under the condition of same content, sintered samples using activated carbon as pore-forming agent had a higher porosity than that with identical content of the other two kinds of pore-forming agents. Sintered samples with 10.0 wt% activated carbon had a porosity of 35%. Section morphologies show that pores distributed uniformly and connected very well in the anode with activated carbon as pore-forming agent. The mechanical strength of these sintered samples with carbon as pore-forming agent was also higher. With the activated carbon particle size decreasing (from 100 mesh to 320 mesh), the open porosity of porous NiO/YSZ was reduced (from 31.7% to 30.9%). It may be concluded that The activated carbon is the better choice as pore-forming agent for NiO/YSZ anode.
Microstructural characterization of yttria-stabilized zirconia plasma-sprayed deposits using multiple small-angle neutron scattering
