【作者】 刘芹芹； 杨娟； 孙秀娟； 程晓农；

【Author】 LIU Qin-qin YANG Juan SUN Xiu-juan CHENG Xiao-nong (School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)

【机构】 江苏大学材料科学与工程学院；

【摘要】 立方晶体结构的钨酸锆具有各向同性的负热膨胀特性,可以和其它材料复合用于制备热膨胀可控的复合材料．采用分步固相法,通过降低氧化物原材料的粒径来合成超细 ZrW₂O₈,比较了不同粒径 ZrW₂O₈的负热膨胀特性．以差热分析仪（DSC）研究了合成过程,以粉末 X 射线衍射（XRD）和扫描电子显微镜分析了 ZrO₂,WO₃ 及立方 ZrW₂O₈的结构和形貌．结果表明,产物 ZrW₂O₈的结构和 NTE 特性取决于原料的粒径．只有以纳米 ZrO₂ 和 WO₃为原材料才能合成出超细 ZrW₂O₈,其具有优异的 NTE 特性．在室温到600℃的温度范围内,超细 ZrW₂O₈ 的热膨胀系数为-7．64×10^-6K^-1,比采用微米级原料合成的 ZrW₂O₈的热膨胀系数(-6．82×10^-6K^-1)大．该方法可用来工业化的生产超细 ZrW₂O₈,使其能够在更广的领域中得到应用．更多还原

【Abstract】 The cubic crystal structure of zirconium tungstate exhibits isotropic negative thermal expansion（NTE）.As a result,ultrafine zirconium tungstate might find use in applications which require tailored thermal expansion properties.In this work,the preparation of ultrafine ZrW₂O₈ powders with different particle size raw oxides materials by step-solid-state reaction and the negative thermal property of the resulted produces were studied.Decomposition behavior of the raw mixture was studied using differential scanning calorimeter（DSC）, the structures of ZrO₂,WO₃ and cubic ZrW₂O₈ were characterized by Powder X-ray diffraction（XRD）,and the morphology of the resulting ZrO₂,WO₃ and ZrW₂O₈ were studied by scanning electron microscope（SEM）.The results show that the NTE property and particle size of the resulted ZrW₂O₈ is depended on the particle size of raw oxides materials.Ultrafine cubic ZrW₂O₈ exhibiting better NTE property could only by obtained using nano ZrO₂ and WO₃ as starting materials.In the temperature range from 20 to 600℃,the thermal coefficient of ultrafine cubic ZrW₂O₈ is —7.64×10^-6K^-1,which bigger than the thermal coefficient ZrW₂O₈(—6.82×10^-6K^-1)prepared by micro ZrO₂ and WO₃.This method can be industrialized to prepare ultrafine cubic ZrW₂O₈ which can be utilized in more fields.更多还原