J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (9): 1602-1608.DOI: 10.1016/j.jmst.2017.12.013

• Orginal Article • Previous Articles     Next Articles

Interfacial failure behavior of PyC-Cf/AZ91D composite fabricated by LSEVI

Shaolin Lia, Lehua Qib*(), Ting Zhangb, Jiming Zhoub, Hejun Lia   

  1. a State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi’an 710072, China;
    b School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
  • Received:2017-10-11 Revised:2017-12-04 Accepted:2017-12-05 Online:2018-09-20 Published:2018-09-25
  • Contact: Qi Lehua

Abstract:

Carbon fiber reinforced AZ91D matrix composites with pyrolytic (PyC) coating deposited on fiber surface (PyC-Cf/AZ91D composites) have been fabricated by Liquid-solid extrusion following vacuum pressure infiltration technique (LSEVI). Interfacial microstructure and failure behavior of the composites were investigated. Instead of interfacial reaction products, block-shaped interfacial precipitates Mg17Al12 were detected at the interface, which indicates that interfacial reaction was restrained by LSEVI and PyC coating. Nano-MgO was detected at the interface. Interfacial failure behavior of the PyC-Cf/AZ91D composites, which was the failure between PyC coating and AZ91D alloy due to the mismatch of thermal expansion and relatively poor bonding, was proposed. Fracture surface of the PyC-Cf/AZ91D composites was characterized by fibers pulling-out tests. PyC coating served not only as protection to the fibers, but also an adjustment of the interface of the composites.

Key words: MMCs, Interface, Carbon fiber, Failure