Yb2Si2O7基复合材料的高温自愈合行为研究-中国材料进展

文章信息/Info

Title:: Research on the High Temperature Self-Healing Behavior of Yb2Si2O7-Based Matrix Composites

作者:: 刘玥豆; 王旭; 刘玲; 马壮; 杨茗佳; 1. 北京理工大学材料学院，北京 100081 2. 北京理工大学冲击环境材料技术国家级重点实验室，北京 100081 3. 北京星航机电装备有限公司，北京 100074

Author(s):: LIU Yuedou; WANG Xu; LIU Ling; MA Zhuang; YANG Mingjia; 1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China 2. National Key Laboratory of Science and Technology on Materials Under Shock and Impact,Beijing Institute of Technology， Beijing 100081, China et al.

Keywords:: Yb2Si2O7; composite material; self-healing; crack; environmental barrier coating

摘要:: SiCf/SiC陶瓷基复合材料满足新一代航空发动机高推重比的发展要求，但在发动机内部高温恶劣环境下，需用环境障涂层对该复合材料进行防护。目前环境障涂层在服役过程中不可避免地会产生裂纹，因此，需要开发一种具有自愈合能力的环境障涂层，在裂纹出现时及时修复。以Yb2Si2O7材料为基础，分别采用放电等离子烧结和无压烧结制备了Yb2Si2O7-SiC和Yb2Si2O7-Yb2SiO5复合陶瓷，开展了Yb2Si2O7基复合材料的自愈合行为研究，并探究了该复合材料作为自愈合环境障涂层材料的可行性。结果表明，向Yb2Si2O7陶瓷中添加SiC第二相时，含5%和10%（质量分数，下同）SiC的Yb2Si2O7-SiC复合材料在空气中1100 ℃热处理1 h后，由于表面的SiC氧化形成SiO2，SiO2的填充作用以及反应引起的体积膨胀促进了裂纹愈合；而在1300 ℃下热处理，SiC大量氧化产生较大体积膨胀，含5%和10% SiC的Yb2Si2O7-SiC复合材料内部反而出现新的裂纹。而向Yb2Si2O7陶瓷中添加Yb2SiO5第二相可以促进材料致密化和裂纹愈合，当Yb2SiO5添加量为50%时，复合材料的裂纹愈合效率最高，约为78%，主要可归因于具有较高热膨胀系数的Yb2SiO5受热膨胀,对Yb2Si2O7产生压应力,促进了裂纹愈合。

Abstract:: SiCf/SiC ceramic matrix composites meet the high thrust-to-weight ratio requirements of next-generation aeroengines but require environmental barrier coatings for protection under extreme high-temperature conditions. Current environmental barrier coatings inevitably develop cracks during service,necessitating self-healing coatings for autonomous crack repair. In this study, based on Yb2Si2O7,Yb2Si2O7-SiC and Yb2Si2O7-Yb2SiO5 were fabricated via spark plasma sintering and pressureless sintering, respectively. The self-healing behavior of these composites was investigated to evaluate their feasibility as environmental barrier coating materials.Results show that adding 5wt%~10wt% SiC to Yb2Si2O7 promoted crack healing after 1 h at 1100 ℃ in air, driven by SiO2 formation from SiC oxidation, which filled cracks through volume expansion. However, at 1300 ℃, excessive SiC oxidation caused significant volumetric stress, generating new cracks within the composites. Yb2SiO5 addition enhanced material densification and crack healing. The composite with 50wt% Yb2SiO5 achieved optimal healing efficiency (78%), attributed to thermally induced compressive stress from higher thermal expansion coefficient of Yb2SiO5. This stress facilitated crack closure in the Yb2Si2O7 matrix.