C_f/ZrB_2-SiC复合材料的高温氧化行为及机理  

Oxidation Resistance Behavior of Short Carbon Fiber Reinforced ZrB_2-SiC Composites

作　　者：许春来[1] 石晓斌[1] 高栋[2] 宋扬[1] 张跃[2] 

机构地区：[1]航天材料及工艺研究所,先进功能复合材料技术国防科技重点实验室,北京100076 [2]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《宇航材料工艺》2011年第1期71-74,79,共5页Aerospace Materials & Technology

摘　　要：将不同比例的ZrB2和SiC粉体充分混合,并在其中均匀分散短切碳纤维(约2 cm),采用热压烧结工艺制备出具有不同ZrB2/SiC比例的短切碳纤维增强超高温陶瓷基复合材料。SiC可显著促进ZrB2陶瓷的烧结致密化程度,添加了18 vol%SiC的ZrB2在1 850℃下热压烧结,致密度达96%以上。对该复合材料分别在1 000、1 200及1 400℃下进行静态氧化实验。结果表明,试样在氧化过程中其表面生成的硼硅酸盐玻璃和ZrO2、SiC等物质在表面形成一层有效的保护膜,因而能够有效阻止材料的进一步氧化。同时,随氧化温度升高和时间延长,氧化过程中形成的硼硅酸盐玻璃量增加,可更有效的覆盖材料表面,提高材料抗氧化能力。Different proportions of ZrB2 and SiC powders were mixed thoroughly and short carbon fibers with length of 2 cm were filled in,then the mixture was hot pressed into ceramic composites with ZrB2 and SiC.Zirconium diboride ceramics containing 18 vol% SiC with high relative density of 96% were prepared by hot pressing method at 1 850℃.The oxidation tests were carried out under 1 000℃,1 200℃and 400℃respectively under ambient atmosphere in order to clarify the oxidation resistance performance.It was found that borosilicate glass,ZrO2 and SiO2 formed on the surface of samples,which acted as an effective oxidized layer preventing further oxidation.With the increase of oxidation temperature and oxidation holding time,the vitreous phase increased during oxidation process to enhance anti-oxidation property.

关 键 词：ZrB2-SiC陶瓷基复合材料 碳纤维 抗氧化性能 氧化膜 

分 类 号：TQ174.758[化学工程—陶瓷工业]