C/C复合材料ZrB_2-SiC基陶瓷涂层制备及烧蚀性能研究  

Preparation and Ablative Behavior of ZrB_2-SiC Based Coatings on C/C Composites

作　　者：张天助[1] 陈招科[1] 熊翔[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中国材料进展》2013年第11期659-664,675,共7页Materials China

基　　金：国家重点基础研究项目(2011CB605805)

摘　　要：为提高C/C复合材料的抗烧蚀性能,采用两步刷涂-烧结法制备了ZrB2-SiC基陶瓷涂层。首先利用反应烧结制备ZrB2-SiC-ZrC过渡层,并在此基础上制备了ZrB2-20%SiC-5%Si3N4、ZrB2-15%SiC-20%MoSi2、ZrB2-15%SiC-20%TaC 3种外涂层。利用XRD和扫描电镜研究了涂层的相组成和显微形貌,并采用氧乙炔焰烧蚀仪测试了涂层在2 500℃、60 s的抗烧蚀性能,探讨了涂层的高温烧蚀机理。结果表明:利用反应烧结制备的过渡层与基体结合紧密,且与外涂层无明显分层现象,起到了良好的过渡作用;由于Si3N4及MoSi2起到了烧结助剂作用,使ZrB2-20%SiC-5%Si3N4、ZrB2-15%SiC-20%MoSi2外涂层结构较为致密;ZrB2-20%SiC-5%Si3N4、ZrB2-15%SiC-20%MoSi2涂层表现出了较好的抗烧蚀性能,其中ZrB2-20%SiC-5%Si3N4涂层线烧蚀率及质量烧蚀率分别为0.075 mm/s、0.008 1 g/s,ZrB2-15%SiC-20%MoSi2涂层线烧蚀率及质量烧蚀率分别为0.018 mm/s、0.0064 g/s,而ZrB2-15%SiC-20%TaC涂层由于结构较为松散,未能起到有效的氧化防护,导致涂层被烧穿。To improve the ablation resistance, ZrB2-SiC coatings were prepared by two-step slurry painting on C/C com- posites. The ZrB2-SiC-ZrC transition layer was prepared by reactive sintering, then ZrB2-20% SIC-5% Si3 N4 , ZrB2-15% SIC-20% MoSi2 , ZrB2-15% SIC-20% TaC outer eoatings were prepared on it. The ablation test was conducted under oxy- acetylene torch at 2 500 ℃ for 60s. X-ray diffractometry and scan electron microscopy were employed to investigate the microstructure and ablation mechanism. The results show that the transition layer has a good combination with the matrix, and no obvious lamination appeared when connected to the outer layer. Owing to the effect of Si3N＂ and MoSi2 as sintering aids, the structure of ZrB2-20% SIC-5% Si3N4 and ZrB2-15% SIC-20% MoSi2 outer coating is quite dense. Coating ZSS and ZSM showed better ablation resistance. The linear ablative rate and mass ablative rate of coating ZSS and ZSM were 0. 075 mm/s, 0. 0081 g/s and 0.018 ram/s, 0. 0064g/s respectively. The coating ZST does not show effective oxidation protection because of its loose structure, and it caused the burning through of the coating.

关 键 词：C C复合材料 ZrB2-SiC涂层 刷涂法 抗烧蚀 

分 类 号：TB332[一般工业技术—材料科学与工程]