• Fox, Bronwyn
• Church, Jeff

Abstract

Carbon fibres and carbon fibre composites are increasingly being used in a broad range of applications, including aerospace, military, engineering and sporting equipment, due to its lightweight, high strength, high modulus, high heat tolerance and chemical resistant properties. More recently, in an effort to reduce weight and thus improve fuel efficiency, carbon fibres have found application in structural components in the commercial aviation and automotive industries. With the increasing demand for carbon fibre comes the need to better understand the correlations between manufacturing parameters and final characteristics of the carbon fibre.Aside from the manufacture of the fibres themselves, which involves thermal oxidative and graphitization steps, the fibre surface is oxidized and sized.Many industrial treatments are highly guarded secrets and commercial in confidence, thus making these important correlations difficult to achieve. The carbon fibre surface treatment and the interactions between the matrix polymer and the carbon surface contribute significantly to the final properties of composites.Many techniques, including X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Surface Energy Analysis (SEA) have been used to gain an understanding of the carbon fibre structure and surface. These methods have short fallings in that they either provide no chemical information or the information is provided at a low spatial resolution. Recent developments in Raman spectroscopy including confocal and area mapping capabilities, has provided the potential to obtain highly spatially resolved (sub micron) chemical and structural information about the fibre surface and possibly information regarding the critical interphase region of the carbon fibre-matrix system.Raman can provide information on the graphitic, disordered and amorphous carbon content of a pure carbon material. There is also potential to obtain information on oxidation species present. Mapping can also be carried out on fibre cross-section providing information about the stabilization and graphitization processes. In this paper we will present the results of several recent studies in which we probe the structure of the carbon fibres surface and its cross-section. The results clearly demonstrate the power of confocal Raman mapping in developing a better understandings of carbon fibre structure.

Topics

• impedance spectroscopy
• surface
• polymer
• amorphous
• Carbon
• scanning electron microscopy
• x-ray photoelectron spectroscopy
• strength
• composite
• transmission electron microscopy
• Raman spectroscopy
• surface energy
• carbon content