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无机材料学报

无机材料学报

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结构陶瓷氧化反应裂纹愈合动力学研究(Ⅲ)模型验证与修正: Al2O3-SiC W陶瓷裂纹愈合动力学研究

吕珺1, 郑治祥1, 吴玉程1, 金志浩2   

  1. 1. 合肥工业大学材料学院, 合肥 230009;
    2. 西安交通大学材料强度国家重点实验室, 西安 710049
  • 收稿日期:2004-12-02 修回日期:2005-02-06 出版日期:2006-05-20 网络出版日期:2006-05-20

Kinetic Research of Oxidation Induced Crack Healing of Engineering Ceramics (Ⅲ) Model Testing and Revising: The Kinetic Research of Al2O3-SiC W Composite

Lü Jun1, ZHENG Zhi-Xian1, WU Yu-Cheng1, JIN Zhi-Hao2   

  1. 1. Materials Science and Engineering Institute, Hefei University of Technology,
    Hefei 230009, China;
    2. State Key Laboratory for Mechanical Behvior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
  • Received:2004-12-02 Revised:2005-02-06 Published:2006-05-20 Online:2006-05-20

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摘要： Al2O3-SiC W 材料通过在高温下发生氧化反应, 生成物所引起的体积膨胀对裂纹处的填充迁移, 使裂纹产生愈合现象. 动力学分析表明: Al2O3-SiC W材料裂纹愈合速度为- Cv/t=(2πC2v0·ΔP+F)/(2πB0Cv)·1/2·(k/t)1/2, 强度恢复由下式计算σf/σf0=[1-(2πC2v0·ΔP+F)/(πB0C2v0)·k1/2·t1/2]-1/4, 与Al2O3-TiC P材料相比, 增加了一个填充项F, 从物理意义上分析, F是除裂纹面外对裂纹愈合有利的填充面积当量, 就Al2O3-SiC W材料而言, F与裂纹面上晶须桥联及晶须露头面积及裂纹周边反应物能够对裂纹处进行填充的面积有关. 1200℃保温时F值约为9.94\times10-8m2.

关键词: 裂纹愈合, 强度, 愈合速度, 氧化反应

Abstract: Oxidation reaction happened when Al2O3-SiC W composite heated at high temperature. The reaction producer moved to the crack area which induced crack healing. The kinetic analysis of crack healing of Al2O3-SiC W composite shows that: the velocity of crack healing can be showed as: - Cv/t=(2πC2v0·ΔP+F)/(2πB0Cv)·1/2·(k/t)1/2, and the strength recovery can be expressed by the following formula: σf/σf0=[1-(2πC2v0·ΔP+F)/(πB0C2v0)·k1/2·t1/2]-1/4. Compared with Al2O3-TiC P composite, the filling coefficient F was added. The physical meaning of F coefficient is the area equivalent except the crack area. For Al2O3-SiC W composite, F is related to the whisker bridge, whisker emerge, and the area on which reaction producer can follow and fill in the crack. When heated at 1200℃, F is about 9.94\times10-8 m2.

Key words: crack healing, strength, velocity of healing, oxidiation reaction

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