Transverse Fracture Behavior of Graphite-Aluminum Composites.

摘要

A determination was made of the transverse tensile strength of graphite-aluminum composites produced from various fiber and matrix compositions and by a variety of processing methods. Processing methods included the standard Ti-B chemical vapor deposition process and modifications to that process, the sodium process, and the nickel-coated fiber method. Precursor rayon, pitch, high-modulus polyacrylonitrile (PAN) and low-modulus PAN fibers were investigated, as well as 201, 6061, and 1100 aluminum-alloy matrices. The transverse fracture strength is influenced by the processing method and the type of fiber but not by the matrix alloy. Those processes and fibers that promote fiber-matrix reaction result in the highest transverse strength. The fractured surfaces, as examined by scanning electron microscopy, revealed fiber-matrix separation and fiber pullout as the dominant features of low-transverse-strength composites. Fiber splitting and the absence of fiber pullout were characteristic of the high-transverse-strength composites. (Author)