Carbon fiber reinforced composites

Most recent studies (69) on elevated temperature performance of carbon fiber-based composites show that the oxidation resistance and elevated temperature mechanical properties of carbon fiber reinforced composites are complex and not always direcdy related to the oxidation resistance of the fiber. To some extent, the matrix acts as a protective barrier limiting the diffusion of oxygen to the encased fibers. It is therefore critical to maintain interfacial bonding between the fiber and the matrix, and limit any microcracking that may serve as a diffusion path for oxygen intmsion. Since interfacial performance typically deteriorates with higher modulus carbon fibers it is important to balance fiber oxidative stabiHty with interfacial performance. 

Pitkethly, M.J. and Doble, J.B. (1990). Characterizing the fiber/matrix interface of carbon fiber-reinforced composites using a single fiber pullout test. Composites 21, 389-395. 

Ko, Y.S., Forsman, W.C. and Dziemianowicz, T.S. (1982). Carbon fiber-reinforced composites effect of fiber surface on polymer properties. Polym. Eng. Sci. 22, 805-814. 

Fig. 8.7. Damage area of 24 ply quasi-isotropic carbon fiber reinforced composite laminates containing different resin matrices. After Srinivasan et al. (1992).

Rccker, H.G., Altstadt, V., Eberle, W., Folda, T., Gerth, D., Heckmann, W., Ittemann, P., Teseh, FI. and Weber, T. (1990). Toughened thermosets for damage tolerance carbon fiber reinforced composites. SAMPE J. 26, 73 78. 

Recall from Section 1.4.5.1 that there are two primary types of carbon fibers polyacrylonitrile (PAN)-based and pitch-based. There are also different structural forms of these fibers, such as amorphous carbon and crystalline (graphite) fibers. Typically, PAN-based carbon fibers are 93-95% carbon, whereas graphite fibers are usually 99+%, although the terms carbon and graphite are often used interchangeably. We will not try to burden ourselves with too many distinctions here, since the point is to simply introduce the relative benefits of continuous-fiber composites over other types of composites, and not to investigate the minute differences between the various types of carbon-fiber-based composites. The interested reader is referred to the abundance of literature on carbon-fiber-reinforced composites to discern these differences. 

Figure 5.107 Variation in toughness and shear strength for various surface treatments of continuous carbon fiber-reinforced composites. Reprinted, by permission, from T. L. Vigo and B. J. Kinzig, ed.. Composite Applications, p. 224. Copyright 1992 by VCH Publishing, Inc.

Some biphenylene end-capped polyquinolines have been used to make carbon-fiber reinforced composites (102). However, properties of these composites dropped off significantly when oxidatively aged for 50—100 h at 316°C. 

Epoxynovolak resin and BPA/DC-BMI prepolymer, tert.butyl peroxide and Zn acetate [106, 107] or 2-phenylimidazole and other catalysts [108] were filled with wollastonite. Carbon-fiber reinforced composites were obtained using a binder, which consisted of BPA/DC, BMI, an epoxynovolak, 2-ethyl-4-methylimidazole and an organic solvent [109]. A BPA/DC-BMI prepolymer in methylethylketone was mixed with middle-molecular-weight epoxide resin (Epikote 1001), 2-ethyl-4-methyl-imidazole, Zn acetate and triethylenediamine thermal shock resistant GRP was thus obtained [110]. 

Figure 7. Comparison of a conventional hip joint fabricated from cobalt alloys with a joint design using carbon-fiber-reinforced composites tailored to meet specific local stress requirements (18) ...

Figure 8. Mechanical properties of various carbon-fiber-reinforced composites compared to bone and some biomedical alloys (20). HM and HT refer, respectively, to fibers of high modulus and high tensile strength.

Poly(ether ether ketone) (PEEK) is a polymer used in carbon fiber reinforced composites. In addition, PEEK has been proposed for use in medical devices(Z). The desirable physical properties of PEEK are its relative insolubility, thermal stability, and toughness. 

FIGURE 12.11 Improvements of the mechanical properties of three-dimensional reinforced CMCs by hybrid infiltration routes (a) R.T. flexural stress-strain plots for a three-dimensional carbon fiber reinforced composite before and after cycles of infiltration (comparison between eight cycles with zirconium propoxide and fonr cycles pins a last infiltration with aluminum-silicon ester (b) plot of the mechanical strength as a fnnction of the final open porosity for composites and matrix of equivalent porosity, before and after infiltration (Reprinted from Colomban, R and Wey, M., Sol-gel control of the matrix net-shape sintering in 3D reinforced ceramic matrix composites, J. Eur. Ceram. Soc., 17, 1475, 1997. With permission from Elsevier) (c) R.T. tensile behavior (d) comparison of the R.T. mechanical strength after thermal treatments at various temperatures. (Reprinted from Colomban, R, Tailoring of the nano/microstructure of heterogeneous ceramics by sol-gel routes, Ceram. Trans., 95, 243, 1998. With permission from The American Ceramic Society.)... 

Carbon fiber reinforced composites are at the forefront of current developments in polymer composites, and there is additional evidence for the important role being played by IGC in characterizing the interface in such systems. The Gutmann theory is used by Bolvari and Ward, who report add/base interactions for surface-treated carbon fibers and a series of thermoplastic polymer hosts, including polysulfone, polycarbonate, and... 

Epoxy resins have found application in carbon fiber reinforced composites for some 30 years or more and the benefits are well documented (Table 5). The traditional limitations are also summarized simply in the same table. 

Applications. Nondestructive method of determination of carbon fiber reinforced composites. Damage of woven fiber reinforced composites, distribution of filler due to flow in molding techniques, distribution of fiber in composite, and dispersion of carbon black are examples characterizing potential applications of the method. 

Kawai M, Yajima S, Hachinohe A, Takano Y. Off-axis fatigue behavior of unidirectional carbon fiber-reinforced composites at room and high temperatures. J Compos Mater... 

Nanocomposite Aerospace Resins for Carbon Fiber-Reinforced Composites... 

Khan ShafiUllah, Li Chi Yin, Siddiqui Naveed A. Kim Jang-Kyo. (2011). Vibration Damping Characteristics of Carbon Fiber-Reinforced Composites Containing Multi-Walled Carbon Nanotubes. Compos. Sci. TechnoL, 71, 1486-1494. 

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