中文摘要：

以Al（OH）3、SiO2为原料，AlF3、V2O5为添加剂在1300℃条件下先制备出莫来石陶瓷粉料；然后向制得的莫来石陶瓷粉料中加入氧化钇稳定的四方相氧化锆（8Y-TZP）粉末，在等离子放电烧结炉（SPS）中烧结制备出致密莫来石陶瓷块体。用X射线衍射仪（XRD）与扫描电子显微镜（SEM）对莫来石陶瓷粉料及块体的物相及微观结构进行表征，结果表明，莫来石粉料的主晶相为莫来石，且含有大量莫来石晶须；在进行SPS烧结时，莫来石晶粒在941℃左右开始熔化，最终以鳞片状形貌结晶析出。当烧结温度为1600℃时，莫来石陶瓷块体的致密度最高可达98.2%；在此温度烧结制得的只含有晶须的样品其断裂韧性可达4.14 MPa·m^1/2，比纯莫来石理论断裂韧性要高；而由莫来石晶须和10wt.%ZrO2制得的陶瓷块体断裂韧性最高可达5.52 MPa·m^1/2，说明晶须与ZrO2能协同增韧莫来石陶瓷。

英文摘要：

Mullite ceramic precursor powder was ifrst prepared by heating raw materials of Al（OH）3, SiO2 and additives of AlF3 and V2O5 at 1300℃. After the addition of yttria-stabilized tetragonal zirconia （8Y-TZP）, densified mullite ceramic was obtained by spark plasma sintering （SPS） of the precursor powder at 1300-1600℃. The phase and microstructure of precursor powder and densiifed mullite ceramics were investigated by X-ray powder diffraction （XRD） and scanning electron microscopy （SEM）. The results showed that the major phase of ceramic precursor powder was mullite, most of which was in the shape of whisker. The mullite precursor （whiskers and grains） began to melt at 941℃ during SPS sintering and ifnally crystallized with lfaky morphology. The highest relative density of the mullite ceramics was 98.2%when the sintering temperature was 1600℃. The fracture toughness of mullite ceramics could increase to 4.14 MPa·m^1/2 when only mullite whisker is added, while the sample with the co-addition of ZrO2 （10 wt.%） and whisker had the largest fracture toughness value of 5.52 MPa·m^1/2. The study indicated that mullite whisker and ZrO2 could co-toughen mullite ceramics.