Oxidation Behaviors of TiB2-TiCx and TiB2-TiC x/15SiC Ceramics
Fully dense samples of TiB2-TiCx and TiB2-TiCx/15SiC ceramic composites were fabricated by in-situ synthesis under hot isostatic pressing from Till2,B4C and SiC powders.Their oxidized behaviors at different temperatures were tested.Optical micrograph studies and thermo-gravimetric analyses show that the highest effective temperature of oxidation resistance is 700℃ for TiB2-TiCx,and 1100℃ for TiB2-TiCx/15SiC.The weight gain of TiB2-TiCx/15SiC below 1100℃ is quite low,and it rises up suddenly when the temperature reaches 1200℃.Thus,the highest effective temperature of oxidation resistance is 1100℃ for TiB2-TiCx/15SiC.The oxidation dynamic curves of TiB2-TiCx/15SiC ceramics accord with the parabolas law.The activation energy of TiB2-TiCx/15SiC (189.87kJ.mol1) is higher than that of TiB2-TiCx (96.44kJ.mol-1).In the oxidation process of TiB2-TiCx/15SiC,TiB2 reacts with oxygen and generates TiO2 and B2O3 at first.A layer of whole homogeneous oxide film cannot be formed,in the mean time,the oxidation of TiC begins.When temperature goes up to 1000℃,TiC phase is totally oxidized.SiC is oxidized to SiO2 at about 900℃,Meanwhile,TiO2 forms denser film than B2O3,which grows and covers the surface of the material,and gives better property of oxidation resistance.
Oxidation behavior TiB2-TiCx/SiC composite Hot isostatic pressing
Degui Zhu Hongliang Sun Yushu Wang Lianghui Wang
Key Laboratory of Advanced Technologies of Materials Ministry of Education, Southwest Jiaotong Unive School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,Beij
国际会议
The Sixth China International Conference on High-Performance Ceramics(第六届中国先进陶瓷国际研讨会(CICC-6))
哈尔滨
英文
179-183
2009-08-16（万方平台首次上网日期，不代表论文的发表时间）