Thermal properties of autoclave and out-of-autoclave carbon fiber-epoxy composites with different fiber weave configurations

Abstract

Thermal expansion, specific heat, diffusivity, and conductivity of carbon fiber-epoxy composites were studied using autoclave and out-of-autoclave prepregs with three different fabric weaves including unidirectional, eight-harness satin, and plain weave. For this purpose, light flash analysis was utilized where the implications of using anisotropic materials were studied. Results indicated that density, thermal expansion, conductivity, and diffusivity were strongly influenced by the fiber configuration of the sample. This phenomenon was attributed to the difference in fiber volume fraction induced by the different weaves of the fabric. Nevertheless, specific heat was similar for all the samples regardless of fabric type or resin formulation. Finally, thermal properties of tetrafluoroethylene release film were presented to analyze the tool-part heat transfer during manufacturing. This release film showed thermal conductivity three times lower than carbon fiber-epoxy samples indicating that the film could be an important contributor to thermal lag between tool and part.

Keywords

Composites thermosets thermal analysis thermal conductivity thermal diffusivity thermal expansion

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References

MatWeb, Graphite, Carbon, C, www.matweb.com (accessed March 2018).

MatWeb, Overview of materials for Epoxy, Cast, Unreinforced, www.matweb.com (accessed March 2018).

Sweeting, R.D. and Liu, X.L., Measurement of thermal conductivity for fibre reinforced composites. Compos Part A Appl S 2004; 35: 933.

Tavakol B, Roozbehjavan P, Ahmed A, Das R, Joven R, Koushyar H, Rodriguez A, and Minaie B. Prediction of residual stresses and distortion in carbon fiber epoxy composite parts due to curing process using finite element analysis. J Appl Polym Sci 2012, 941–950.

Scott EP and Beck JV. Estimation of thermal properties in carbon/epoxy composite materials during curing. J Compos Mater 1992; 20: 20–36.

Bogetti TA and Gillespie JW. Two-dimensional cure simulation of thick thermosetting composites. J Compos Mater 1991; 239: 239–273.

Scott EP and Beck JV. Estimation of thermal properties in carbon/epoxy composite materials during curing. J Compos Mater 1992; 20: 20–36.

Friis-Pedersen HH, Pedersen JH, Haussler L and Storm BK. Online measurement of thermal diffusivity during cure of an epoxy composite. Polym Test 2006; 8: 1059–1068.

Garnier B and Sommier A, Thermal property measurements during curing of thermoset resins using steady periodic conditions. J Reinf Plast Compos 2002; 21: 1193–1203.

10.

Koushyar H, Alavi-Soltani, S, Minaie B and Violette M. Effects of variation in autoclave pressure, temperature, and vacuum-application time on porosity and mechanical properties of a carbon fiber/epoxy composite. J Compos Mater 2012; 46: 16.

11.

Parker WJ, Jenkins RJ, Butler CP and Abbott GL. Flash method of determining thermal diffusivity, heat capacity, and thermal conductivity, J Appl Phys 1961; 32: 1679–1684.

12.

Pinto CSC, Massard H, Couto P, Orlande HRB, Cotta RM and Ambrosio MCR. Measurement of thermophysical properties of ceramics by the flash method. Braz Arch Biol Technol 2006; 49: 31–40.

13.

Cowan RD. Pulse method of measuring thermal diffusivity at high temperatures. J Appl Phys 1962; 4: 926–928.

14.

Mehling H, Hautzinger G, Nilsson O, Fricke J, Hofmann R and Hahn O. Thermal diffusivity of semitransparent materials determined by the laser-flash method applying a new analytical model. Int J Thermophys 1998; 19: 941–949.

15.

Cape JA and Lehman GW. Temperature and finite pulse-time effects in the flash method for measuring thermal diffusivity. J Appl Phys 1963; 34: 1909–1914.

16.

Department of Defence. MIL-HDBK-17-1F “composite materials handbook” Vol. 1. Polymer matrix composites guidelines for characterization of structural materials, 2002.

17.

Sun B, Liu F and Gu B. Influence of the strain rate on the uniaxial tensile behavior of 4-step 3d braided composites. Compos Part A Appl S 2005; 36: 1477–1485.

18.

Ahmed AU. Resin flow velocity measurement of carbon fiber/epoxy composites in autoclave processing. Master's Thesis, Wichita State University, USA, 2012.

19.

Duncan M and Price MJ. Thermal Conductivity of PTFE and PTFE Composites, In: Proceedings of the Twenty-Eight Conference of the North American Thermal Analysis Society: Orlando, FL. 2000.

20.

Alway-Cooper RM, Theodore M, Anderson DP and Ogale AA. Transient heat flow in unidirectional fiber -polymer composites during laser flash analysis: experimental measurements and finite element modeling. J Compos Mater 2012; 47: 19.