Thermal barrier coatings (TBC) are plasma sprayed onto gas turbine parts in order to improve combustion efficiency and component life time. Two TBC are looked at in this report: yttria partially stabilized zirconia (YPSZ) and dysprosia partially stabilized zirconia (DyPSZ). Both the TPS and laser flash techniques were used to measure the thermal conductivity of the coatings and the results were compared. In addition the effect of barrier microstructure on ...
Yttria-stabilized zirconia (YSZ) powders containing varying amounts of SiO2 and Al2O3 impurities were plasma sprayed onto metallic substrates and subsequently investigated. The authors were interested in how the impurities affected sintering rates, thermal conductivity, linear contraction, and pore size and architecture among other things. The YSZ coatings were heat treated at 1400°C for 10 hours and then analyzed for the properties mentioned above. A machine was used to measure the ...
Using industrial grade mullite powder and a foaming and starch consolidation process, a series of porous mullite ceramics were prepared. These ceramics were analyzed by a thermal constants analyzer, and it was determined that the ceramics had low thermal conductivities and would make good thermal insulators. The porosity of the synthesized ceramics can be controlled by the sintering temperature and by adjusting solid loading. The ceramics were subjected to theoretical ...
This thesis looked at the relationship between thermal conductivity and compression and saturation in three different fuel cell diffusion media (DM). The stress-strain relationship of the materials was investigated using an optical microscope, and thermal conductivity was measured by a thermal constants analyzer. A theoretical model of the maximum through-plane thermal conductivity was developed as a function of compression and saturation....
Through the use of the salt-leaching pore forming method, a series of sintered nickel capillary wicks with variable porosity and pore characteristics were synthesized. The thermal conductivities of these wicks (both dry and wet) were evaluated by the transient plane source (TPS) method. The factors that affect thermal conductivity were found to be the porosity and the pore size distribution....
