Effect of Liquid Phase Impregnation Coatings on the Interfacial Bonding Strength of Carbon Fiber-Reinforced Aluminum

Liquid Phase Impregnation (LPI) fiber coatings applied as thin solid films are found to modify the fracture toughness of carbon fiber reinforced AlSi5 composites in a previous study. In order to quantify the influence of these fiber treatments on the interfacial bonding strength of the composites, samples from coated and untreated fibers (reference) are characterized through fiber push-out technique. Glassy carbon and silicon oxycarbide coatings lead to a reduction of the interfacial bonding strength of 81% and 83%, respectively, in comparison to the reference sample. A fractographic study of the tested specimens by means of Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDX) identifies the adhesive failure at the fiber/coating contact as predominant failure mode of the system.