CeO_(2)/MoSi_(2)改性ZrB_(2)-SiC陶瓷的烧结性能及耐烧蚀性能  

Sintering Property and Anti-Ablation Resistance of ZrB_(2)-SiC Ceramics Modified by CeO_(2)/MoSi_(2)

作　　者：方婉娴 曾晨 张泽 张明瑜[1] 黄启忠[1] 高莹[2] FANG Wanxian;ZENG Chen;ZHANG Ze;ZHANG Mingyu;HUANG Qizhong;GAO Ying(Powder Metallurgy Research Institute,Central South University,Changsha 410083,China;Beijing Sinoma Synthetic Crystals Co.,Ltd.,Beijing 100018,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]北京中材人工晶体研究院有限公司,北京100018

出　　处：《硅酸盐通报》2024年第5期1937-1949,共13页Bulletin of the Chinese Ceramic Society

基　　金：长沙市自然科学基金(kq2208269)。

摘　　要：无压烧结ZrB_(2)-SiC陶瓷可制备复杂形状构件,但致密化难且耐烧蚀性能有待提高,因此亟需研究能够改善陶瓷致密化的有效烧结助剂。本文采用CeO_(2)和MoSi_(2)为烧结助剂,在1850℃无压烧结1 h条件下制备了ZrB_(2)-SiC陶瓷,研究了CeO_(2)和MoSi_(2)对ZrB_(2)-SiC陶瓷烧结性能和耐烧蚀性能的影响。结果表明,当5%(体积分数)的烧结助剂中CeO_(2)和MoSi_(2)体积比为1∶1时,ZrB_(2)-SiC陶瓷的烧结性能、耐烧蚀性能最佳。烧结助剂在烧结过程中形成Ce-Mo液相,陶瓷颗粒在液相的表面张力下重排和传质,Ce-Mo液相促进陶瓷颗粒在毛细力下形成烧结颈,填充于陶瓷颗粒的间隙中,并在降低陶瓷晶粒的晶界能时促进致密化进程,最终获得无压烧结密度为5.02 g/cm^(3)、相对密度为89.71%、维氏硬度为14.04 GPa的ZrB_(2)-SiC陶瓷。相对于未添加烧结助剂时,实际密度提高了53%,维氏硬度提高了43%。在烧蚀过程中,烧结助剂适量补充SiO_(2)后可促进黏度适宜的玻璃相自愈合,并提高ZrO_(2)的稳定性,使ZrB_(2)-SiC陶瓷具有最好的耐烧蚀性能,此时ZrB_(2)-SiC陶瓷质量烧蚀率为-1.62 mg/s,线烧蚀率为0.33μm/s。Pressureless sintered ZrB_(2)-SiC ceramics can be prepared as complex shaped component.But they are challenging to densify and have poor anti-ablation resistance.Therefore,there is an urgent need to investigate effective sintering aids to improve the densification of ceramics.ZrB_(2)-SiC ceramics were prepared by pressureless sintered at 1850℃for 1 h using CeO_(2)and MoSi_(2)as sintering aids.The effects of CeO_(2)and MoSi_(2)on sintering properties and anti-ablation resistance of ZrB_(2)-SiC ceramics were investigated.The results show that sintering properties and anti-ablation resistance of ZrB_(2)-SiC ceramics are best when the ratio of CeO_(2)and MoSi_(2)in 5%(volume fraction)sintering aid is 1∶1.Sintering aids form a Ce-Mo liquid phase during the sintering process.Ceramic particles are rearranged and mass transferred under the surface tension of the liquid phase.The Ce-Mo liquid phase promotes the formation of sintered necks under capillary forces,filles the interstices of the ceramic particles and reduces the grain boundary energy of the ceramic grains to facilitate the densification process.ZrB_(2)-SiC ceramics are ultimately obtained with an density of 5.02 g/cm^(3),a relative density of 89.71%,and a Vickers hardness of 14.04 GPa.The actual density and Vickers hardness increases by 53%and 43%,respectively,compared to when no sintering aid is added.During the ablation process,CeO_(2)and MoSi_(2)supplemented SiO_(2)in appropriate amounts to promote self-healing of the glassy phase with suitable viscosity and improve the stability of ZrO_(2).The mass ablation rate and the line ablation rate are-1.62 mg/s and 0.33μm/s,respectively.

关 键 词：ZrB_(2)-SiC CeO_(2)/MoSi_(2)改性 烧结性能 耐烧蚀性能 无压烧结 注浆成型 

分 类 号：TB332[一般工业技术—材料科学与工程]