Gd_2O_3-NiO共掺对钇稳定氧化锆材料热物理性能的影响

Influence of Gd_2O_3-NiO Co-doping on Thermal Physical Properties of Zirconia-based Ceramic Materials

目的研究Gd2O3-NiO共掺对钇稳定氧化锆材料热物理性能的影响。方法采用高温固相反应法制得Gd2O3-NiO共掺YSZ陶瓷材料。分别利用XRD、扫描电镜观察、激光导热仪、傅立叶红外光谱仪对陶瓷材料的晶体结构、微观结构、热扩散系数及红外透过率进行表征,并对其热导率进行分析。结果 Gd2O3-NiO共掺YSZ后,陶瓷材料单斜相含量减少,室温至1300℃的热导率相比YSZ降低,在2.5-5μm波长范围内红外透过率降低。结论 Gd2O3-NiO共掺对YSZ陶瓷材料热导率的影响机理为掺杂Gd2O3和NiO导致YSZ中单斜相（M）、四方相（T）和立方相（C）含量发生变化,同时YSZ晶格发生畸变。对YSZ辐射传热的影响机理为通过在YSZ中掺杂过渡金属元素Ni使陶瓷材料吸收特定波长的光,进而有效地降低在2.5-5μm短波长的红外透过率,降低其高温下的红外辐射传热。

Objective To study the influence of Gd2O3-Ni O co-doping on thermal physical properties of zirconia-based ceramic materials. Methods Gd2O3-Ni O co-doped YSZ（contain 3.5%Y2O3, mol fraction）（GN-YSZ）was prepared by solid phase synthesis method.The crystal structure and phase composition of the GN-YSZ were studied by XRD analysis. The microstructure was analyzed by SEM. The thermal diffusivities of ceramic materials were tested by laser-flash method. The infrared transmittance was studied by infrared transmittance instrument. Results The results showed that after Gd2O3-Ni O co-doping of YSZ, the content of monoclinic phase（M） was decreased, the thermal conductivity in the temperature range of room temperature to 1300 ℃ was reduced, and the infrared transmittance of ceramics materials in the wavelength range of 2.5 μm-5 μm was also reduced. Conclusion The influencing mechanism of doping oxides on the thermal physical property of YSZ was that co-doping with Gd2O3 and Ni O resulted in lattice distortion and content variation of monoclinic phase（M）, tetragonal phase（T） and cubic phase（C） in YSZ. The influencing mechanism of the radioactive heat transfer was that doping transition metallic Ni O led to an optical absorption at the particular wavelengths. That was why transition metallic elements such as Ni2＋ site could effectively reduce the transmittance of GN-YSZ ceramics at short wavelengths, while reduce infrared radioactive heat transfer at high temperature.