无压烧结制备ZrB_(2)-SiC复相陶瓷及性能研究

Preparation and Properties of ZrB_(2)-SiC Composite Ceramics by Pressureless Sintering

以ZrB_(2)、SiC微粉为主要原料,以酚醛树脂为粘结剂,B4C为烧结助剂,采用冷等静压成型-无压烧结的制备工艺成功制备出ZrB_(2)-SiC复相陶瓷。研究了酚醛树脂的加入量对ZrB_(2)-SiC复相陶瓷的显微结构以及力学性能的影响,通过空气等离子烧蚀试验测试了复相陶瓷的抗氧化性能。结果表明,酚醛树脂在800℃下进行缓慢裂解,可以起到维型的作用,同时产生的孔洞最少;在酚醛树脂的加入量为6 wt.%的条件下,采用无压烧结工艺制备的ZrB_(2)-SiC复相陶瓷内部结构相对致密,气孔细小,元素分布相对均匀,体积密度达到95.3%,最大抗弯强度达到488 MPa,并表现出优异的抗氧化性能。

ZrB_(2)-SiC composite ceramics were successfully prepared using ZrB_(2)and SiC micropowders as the main raw materials,phenolic resin as the binder,and B4C as the sintering aid,through a process of cold isostatic pressing followed by pressureless sintering.The study investigated the influence of the amount of phenolic resin added on the microstructure and mechanical properties of the ZrB_(2)-SiC composite ceramics.The oxidation resistance for ceramics was also tested using an air plasma ablation experiment.The results showed that the phenolic resin undergoes slow pyrolysis at 800℃,which helps to maintain the shape while producing minimal porosity.With the addition of 6wt.%phenolic resin,the ZrB_(2)-SiC composite ceramics prepared by pressureless sintering exhibited a relatively dense internal structure with fine pores and uniform element distribution.The bulk density reached 95.3%,with a maximum flexural strength of 488 MPa,and exhibited excellent oxidation resistance.