ZrW_2O_8/ZrO_2可控热膨胀复合材料的制备  

Preparation of ZrW_2O_8/ZrO_2 composites with controllable thermal expansion

作　　者：杨新波[1] 程晓农[1] 严学华[1] 

机构地区：[1]江苏大学材料科学与工程学院,镇江212013

出　　处：《复合材料学报》2007年第3期147-153,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(5037202750442023)

摘　　要：采用分步加热固相法成功制备了纯度较高的各向同性负热膨胀材料ZrW2O8。将ZrW2O8与ZrO2按一定比例混合,在1200℃烧结24 h制备了热膨胀系数可控的ZrW2O8/ZrO2复合材料。研究结果表明,通过改变ZrW2O8的体积分数,ZrW2O8/ZrO2复合材料的热膨胀系数可以控制为负、正或零。当ZrW2O8的体积分数为37%时,复合材料的热膨胀系数接近零。为了得到致密的ZrW2O8/ZrO2复合陶瓷,采用Al2O3作为烧结剂,取得了较好的效果。0.35 wt%Al2O3的加入可以在不影响复合材料热膨胀性能的前提下,显著提高复合材料的致密度。ZrW2O8 which exhibits excellent isotropic negative thermal expansion was synthesized using the step by step solid state reaction. The ZrW2O8/ZrO2 composites with controllable thermal expansion coefficient were prepared by mixing ZrW2O8 and ZrO2 at different volume ratios and sintered at 1200℃ for 24 h. The thermal expansion coefficient of ZrW2O8/ZrO2 composites can be controlled, being negative, positive or even zero, by adjusting the volume fraction of ZrW2O8. The ZrW2O8/ZrO2 composites show almost zero thermal expansion when the volume fraction of ZrW2O8 is 37%. In order to obtain dense and tough ZrW2O8/ZrO2 ceramic, AlzO3 was adopted as an additive. The results reveal that it is effective to improve the density of the composites. 0.35 wt% Al2O3 additive can increase the density of the composites rapidly with slight effects on the thermal expansion property.

关 键 词：可控热膨胀 负热膨胀 ZRW2O8 复合材料 ZRO2 

分 类 号：TB332[一般工业技术—材料科学与工程]