航空学报 > 2017, Vol. 38 Issue (11): 221197-221197   doi: 10.7527/S1000-6893.2017.221197

高密度脉冲电流对SiCp/Al板材裂纹的修复作用

易卓勋, 赖小明, 王博, 张加波   

  1. 中国空间技术研究院 北京卫星制造厂, 北京 100094
  • 收稿日期:2017-02-28 修回日期:2017-07-20 出版日期:2017-11-15 发布日期:2017-07-20
  • 通讯作者: 王博 E-mail:wangb529@126.com
  • 基金资助:

    国家自然科学基金(51405487)

Effect of high density pulse current on healing of cracks of SiCp/Al composites

YI Zhuoxun, LAI Xiaoming, WANG Bo, ZHANG Jiabo   

  1. Beijing Spacecrafts, China Academy of Space Technology, Beijing 100094, China
  • Received:2017-02-28 Revised:2017-07-20 Online:2017-11-15 Published:2017-07-20
  • Supported by:

    National Natural Science Foundation of China (51405487)

摘要:

针对SiCp/Al材料塑性低、容易产生裂纹的缺陷,研究了高密度脉冲电流对SiCp/Al板材裂纹的修复作用。采用室温拉伸方法预制裂纹,在扫描电子显微镜(SEM)下标定裂纹后,对试样进行脉冲电流(电流密度为31.25 A/mm2)处理,对比分析脉冲电流处理前后裂纹形貌,测试电流处理对含裂纹试样力学性能的影响。结果显示,脉冲电流处理后,试样表面尺寸较小的裂纹直接被焊合,尺寸较大的裂纹宽度减小并且尖端出现了熔化现象;对比试样脉冲电流处理前后的延伸率发现,脉冲电流处理可以使试样预变形后的延伸率提高38%。采用电-热-力耦合的数值分析方法求得通电后SiCp/Al板材裂纹附近的电流场、温度场和应力场,并进行了脉冲电流处理对裂纹修复的机理分析,为脉冲电流修复技术的应用奠定理论基础。

关键词: 铝基碳化硅复合材料, 裂纹修复, 脉冲电流, 延伸率, 数值模拟

Abstract:

In order to solve the problem that SiCp/Al composites is low in plasticity and prone to crack, Specimens of SiCp/Al composites with drawing cracks are used to perform healing experiment by high density (31.25 A/mm2) pulse current treating. After pre-cracking with mechanical tensile at room temperature, the Scanning Electron Microscope (SEM) figures of the cracks taken before and after the healing are compared. The effects of pulse current treating on the mechanical properties are studied. Experimental results show that the local closure, the decrease in width and local melting around the crack tip are observed after a high density pulse current was applied to a specimen. The specific elongation of the specimen with the crack increases by 38% after healing. Based on the coupled current-thermal-structural theory, a numerical simulation method is proposed to study the electric current field, the temperature field and the stress field around the crack of the SiCp/Al sheet. Based on the results of numerical simulation, the mechanism of healing crack with pulse current is studied to provide some foundation for application of high density pulse current healing techniques.

Key words: SiCp/Al composites, crack healing, pulse current, elongation, numerical simulation

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