化学共沉淀法合成低热膨胀ZrW2O8/ZrO2复合材料

采用化学共沉淀法合成前驱体，前驱体经1150℃烧结得到ZrW₂O₈/ZrO₂复合材料。对ZrW₂O₈/ZrO₂前驱体进行傅里叶变换红外光谱、热重-差示扫描量热分析；通过X射线衍射仪(XRD)、扫描电镜(SEM)、能谱仪(EDS)和热膨胀仪对合成样品的晶体结构、断面形貌和热膨胀性能进行表征。研究结果表明:合成的复合材料的组元为α-ZrW₂O₈和m-ZrO₂相，化学均匀性良好且易烧结；随着ZrW₂O₈质量分数增加，复合材料的热膨胀系数减小，其中26%ZrW₂O₈/ZrO₂复合材料在30~600℃的平均热膨胀系数为-0.5649×10-6K-1，近似为0。 

Synthesis of Synthesis of ZrW2O8/ZrO2 composites with low thermal expansion using chemical co-precipitation method

ZrW2O8/ZrO2 composites were prepared by calcining the precursor synthesized by the chemical co-precipitation method at 1150℃ for 3.5 h. The precursor of ZrW2O8/ZrO2 was studied by Fourier transform infrared spectroscopy(FTIR) and thermogravimetric and differential scanning calorimetry(TG-DSC). The crystal structure，section morphology and thermal expansion properties of the synthesized composites were investigated by X-ray diffraction (XRD)，scanning electron microscopy (SEM)，energy dispersive spectrometer(EDS) and dilatometry. The results indicate that the obtained composites contain only α-ZrW2O8 phase and m-ZrO2 phase without other phases，which have good chemical uniform and sintering ability. The average thermal expansion coefficient of ZrW2O8/ZrO2 composites decreases with the increase of mass fraction ofZrW2O8. Among all the samples，26%ZrW2O8/ZrO2 composites exhibit nearly zero thermal expansion，and the average thermal expansion coefficient is -0.5649 10-6K-1 from 30℃ to 600℃.