Dy_2O_3改性YSZ相稳定性及熔盐腐蚀行为

以固相烧结法制备不同含量Dy_2O_3掺杂的YSZ陶瓷材料(DYSZ),通过XRD和SEM等表征手段研究了DYSZ材料的相稳定性及熔盐腐蚀行为.结果表明:在1500℃热处理24 h后,Dy_2O_3摩尔分数为6%的DYSZ材料有少量单斜相出现,随着掺量的增加,材料表现良好的相稳定性;在低温老化处理过程中,DYSZ材料具有较8YSZ材料更好的相稳定性.在熔盐腐蚀条件下,稳定剂Dy_2O_3优先析出与V2O5熔盐反应生成DyVO4,造成t/c-ZrO2向单斜相转变,相变应力及腐蚀产物生成与不规则生长造成材料的开裂失效.

Phase Stability and Molten Salt Corrosion Behavior of YSZ Modified by Dy_2O_3

Yttria-stabilized zirconia with doping different content of Dy_2O_3(DYSZ) was prepared by solid state sintering method. The phase stability and molten salt corrosion behavior of DYSZ were characterized by XRD and SEM techniques. Results showed that some new diffraction peaks ascribed to monoclinic phase appeared in the YSZ with doping 6% of Dy_2O_3 after annealing at 1500 ℃ for 24 h. The phase stability of the samples improved with the increase of Dy_2O_3 content. During the hydrothermal degradation, the DYSZ materials had better phase stability than the 8 YSZ material.Under molten salt corrosion conditions, V_2O_5 preferentially reacted with Dy_2O_3 to form DyVO_4, leading to cubic tetragonal to monoclinic.Phase transformation stress, formation and irregular growth of the resultant DyVO_4 crystals could accelerate the material degradation.