Microstructure and tensile behavior of 2D-C_f/AZ91D composites fabricated by liquid–solid extrusion and vacuum pressure infiltration

Shaolin Li¹，Lehua Qi²，Ting Zhang¹，Jiming Zhou²，Hejun Li¹

1. State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University2. School of Mechatronic Engineering, Northwestern Polytechnical University

摘 要：2D carbon fiber reinforced AZ91 D matrix composites（2D-C_f/AZ91 D composites） were fabricated by liquid–solid extrusion and vacuum pressure infiltration technique（LSEVI）. In order to modify the interface between fibers and matrix and protect the fiber, pyrolytic carbon（Py C） coating was deposited on the surface of T700 carbon fiber by chemical vapor deposition（CVD）. Microstructure observation of the composites revealed that the composites were well fabricated by LSEVI. The segregation of aluminum at fiber surface led to the formation of Mg₁₇Al₁₂ precipitates at the interface. The aluminum improved the infiltration of the alloy and Py C coating protected the fibers effectively. The ultimate tensile strength of 2D-C_f/AZ91 D composites was about 400 MPa. The fracture process of 2D-C_f/AZ91 D composites was transverse fiber interface cracking–matrix transferring load–longitudinal fibers bearing load–longitudinal fibers breaking.

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