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无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

Si3N4颗粒及SiC晶须强韧化MoSi2复合材料的低温氧化行为

周宏明1,2, 柳公器1, 肖来荣1, 易丹青1, 曾 麟1   

  1. （中南大学1. 材料科学与工程学院; 2. 粉末冶金国家重点实验室, 长沙 410083）
  • 收稿日期:2009-01-12 修回日期:2009-02-23 出版日期:2009-09-20 网络出版日期:2009-09-20

Low Temperature Oxidation Behavior of MoSi2 Composites Strengthened and Toughened by Si3N4 Particles and SiC Whiskers

ZHOU Hong-Ming1,2, LIU Gong-Qi1, XIAO Lai-Rong1, YI Dan-Qing1, ZENG Lin1   

  1. (1. School of Materials Science and engineering, Central South University, Changsha 410083, China; 2. State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China)
  • Received:2009-01-12 Revised:2009-02-23 Published:2009-09-20 Online:2009-09-20

PDF (PC)

1617

被引次数

3

摘要： 对Si3N4颗粒及SiC晶须强韧化MoSi2复合材料在773K下的氧化行为进行了研究.通过热重量分析法（TG）分析了MoSi2及其复合材料MoSi2-Si3N4(p)和MoSi2-Si3N4(P)SiC(w)在773K下的氧化性能, 采用SEM和X射线衍射测定其表面形貌和氧化物相组成.结果发现：在773K下, 纯MoSi2和MoSi2+20vol%Si3N4均发生了“Pesting”氧化, 氧化过程服从直线规律, 氧化产物层疏松, 氧化产物主要为MoO3; MoSi2+40vol%Si3N4氧化服从抛物线规律, 速率常数Kp为0.04mg2/(cm4·h), 氧化层致密, 成分主要为SiO2、Si2N2O, 增加Si3N4的含量可显著提高MoSi2的抗“Pesting”氧化能力; MoSi2+20vol%Si3N4+20vol%SiC发生了严重的粉化现象, 氧化产物主要为短针状MoO3.

关键词: MoSi2, 复合材料, 低温氧化, Pesting, 热力学

Abstract: The oxidation behavior of MoSi2 composites strengthened and toughened by Si3N4 particles and SiC whiskers was investigated. The oxidation performances of pure MoSi2, MoSi2-Si3N4(p) and MoSi2+20vol%Si3N4+20vol%SiC at 773K were analyzed by thermo gravimetric analysis(TG). The surface micrograph and phases of the oxidation productions were analyzed using by SEM and X-ray. “Pesting” phenomena are observed in the pure MoSi2 and MoSi2+20vol%Si3N4 after oxidation, the relationship between gain weight and oxidation time is followed the straight-line law. The oxidation layer is loose and the main oxidation production is MoO3. While the relationship between the gain weight and oxidation time is followed parabolic law during the oxidation of MoSi2+40vol%Si3N4 and the oxidation rate is 0.04mg2/(cm4·h). The oxidation layer is dense and the main oxidation productions are SiO2 and Si2N2O. So the resistance to “Pesting” oxidation will increase with the content of Si3N4 increasing. There happens serious “Pesting” in the MoSi2+20vol%Si3N4+20vol%SiC after oxidation and the main oxidation production is short acicular MoO3.

Key words: MoSi2, composite materials, low temperature oxidation, pesting, thermodynamics

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