Estudo do tratamento superficial de fibras de carbono para aplicação no setor aeronáutico

Abstract

Carbon fibers have unique properties and are the subject of research that reconciles art, science and technology. One of its most valuable applications is reinforcement in composites of thermosetting matrix in the aeronautical sector. The study to improve the interfacial adhesion between reinforcement and the matrix, since the interface is the place where more structural failures occur, is an important advance for the area of composite materials. The objective of this work was the application of an oxidative surface treatment in carbon fibers using nitric acid, where carbon fibers with 3K filaments and 12K filaments were used. The application time was 60 minutes and the methodology used was by immersion. After the appropriate surface treatment, cleaning and drying, composites were made using epoxy resin as support. The same was done using carbon fibers without surface treatment for the comparison of the mechanical and morphological properties. Traction tests, pycnometry, energy dispersive X ray spectroscopy and scanning electron microscopy were applied for the study of interfacial adhesion enhancement. Efficient surface morphological changes were achieved in carbon fibers, altering the roughness and percentages of chemical elements that will interact with the epoxy resin. The values of the mechanical properties, such as tensile strength and modulus of elasticity, increased by 11% and 26% for the composites using the treated 3K carbon fibers and a 6% and 16% increase for the composites that used the 12K carbon fibers treated.