Some Atomistic Observations on the Role of Titanium in Magnesium-Graphite Fiber Composites

摘要

Titanium, when used as a fiber coating, has been found to effectively promote wetting and bonding between graphite fibers and magnesium, thereby permitting the fabrication of magnesium-graphite fiber composites having significantly improved strength and stiffness. This report presents an atomistic analysis of the role of titanium in this composite system. To this end, the fiber-matrix interfacial compounds that could be formed when molten magnesium is brought into contact with Ti-coated graphite fibers are deduced from atomistic, thermodynamic, and crystallographic data. Comparison of theory and experiment indicates that the sound bonding attained in this system could result from any of the possible atomistic hypotheses proposed. This analysis provides a basis for understanding the mechanisms by which excellent fiber-matrix wetting and bonding have been achieved by the use of a titanium intermediate layer in the fabrication of this composite system. (Author)