ZHAO Mengtian, LONG Yun, WANG Yuzhang
(School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract: Rare earth element Sc doping can effectively improve the phase stability and salt spray corrosion resistance of YSZ. The thermal conductivity of YSZ was studied by non-equilibrium molecular dynamics simulation method. The effects of simulation system size, simulation temperature, Y2O3 doping content, nanopore and Sc2O3-Y2O3 co-doped ratio on thermal conductivity of YSZ were discussed. The results show that the size of the simulation system has certain influence on the thermal conductivity so that an appropriate simulation size should be chosen to ensure the relative accuracy of the results; the increase of Y2O3 doping content and simulation temperature will reduce the thermal conductivity of YSZ while the decreasing trend of thermal conductivity gradually slows down; the thermal conductivity decreases by 36.6% when the porosity is 17.78%, and the thermal insulation effect and structural stability of small size nanopore are better than that of large size nanopore; when the total doping content of Sc2O3 and Y2O3 is 8 mol%, the doping ratio of Y2O3 and Y2O3 has little effect on thermal conductivity.
Key words: yttria-stabilized zirconia; thermal barrier coatings; molecular dynamics; doping