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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2017, Vol. 38 ›› Issue (11): 221197-221197.doi: 10.7527/S1000-6893.2017.221197

• Solid Mechanics and Vehicle Conceptual Design • Previous Articles     Next Articles

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)

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

CLC Number: