N. Oya, D.J. Johnson /Carbon 39(2001)635-645 Mechanical and physical properties of PAN-based carbon fibres Diameter Tensile strength Tensile modulus train-to-failure (g/cm 7.01 1.75 237 4.97 T1000 7.1 M40 5.2 M60J 194 Fibre diameter measured by SEM assuming a circular cross section. Tensile properties based on ASTM D-3379 Density supplied by the manufacturer. of compressive strength in carbon fibres by means of a showing the highest Youngs modulus. All fibres are similar direct technique commercially available from Toray Industries, Inc 2.2. Single fibre compression test 2. Experimenta In the previous study [3], a compression device was constructed for single carbon fibres using a cantilever 2. 1. Carbon fibres used beam with strain gauges attached and a minimotor-cam The cantilever beam was moved laterally towards a fixed Seven kinds of PAN-based carbon fibres including four fibre sample with a rotation of the elliptical cam, and the high strength(HS)and three high modulus(HM)fibres strain gauges detected the small force applied on the were investigated. The physical properties of these fibres sample. However, that device had problems concerning a are presented in Table 1. HS fibres have substantially fast rate of loading, possible misalignment of fibres, and improved tensile strength whereas their tensile modulus inaccurate gauge-length determination. As suggested then has not changed greatly. It should be noted that T700S and further modifications were needed to obtain a more cor T1000 were supplied as epoxy-sized. HM fibres show trolled loading motion and in-situ micro observa- higher tensile modulus in the order of M40J, M50J and tions in order to have accurate sample gauge-length and M60J, but their tensile strength decreases in the same better understanding of the compressive failure behaviour order. As seen from density values in HM fibres, M60J of carbon fibres presumably has the most crystallite layers packed as aA schematic diagram of the present compression result of the highest graphitization temperature, thus is shown in Fig. 1. Firstly, a single carbon fibre Brass stage train gauges (Top view of the sample stage) Cantilever beam Disk stage Reduction stag reduction gear Fig. 1. Compression device for single carbon fibre636 N. Oya, D.J. Johnson / Carbon 39 (2001) 635 –645 Table 1 Mechanical and physical properties of PAN-based carbon fibres ab b c Diameter Tensile strength Tensile modulus Strain-to-failure Density3 (mm) (GPa) (GPa) (%) (g/cm ) T300 7.01 3.5 210 1.68 1.75 T700S 6.75 5.3 237 2.23 1.82 T800H 4.97 6.4 306 2.19 1.81 T1000 5.00 7.1 294 2.40 1.82 M40J 5.21 4.9 335 1.45 1.77 M50J 5.19 4.3 430 1.00 1.88 M60J 5.07 3.5 535 0.65 1.94 a Fibre diameter measured by SEM assuming a circular cross section. b Tensile properties based on ASTM D-3379. c Density supplied by the manufacturer. of compressive strength in carbon fibres by means of a showing the highest Young’s modulus. All fibres are similar direct technique. commercially available from Toray Industries, Inc. 2.2. Single fibre compression test 2. Experimental procedures In the previous study [3], a compression device was constructed for single carbon fibres using a cantilever 2.1. Carbon fibres used beam with strain gauges attached and a minimotor-cam. The cantilever beam was moved laterally towards a fixed Seven kinds of PAN-based carbon fibres including four fibre sample with a rotation of the elliptical cam, and the high strength (HS) and three high modulus (HM) fibres strain gauges detected the small force applied on the were investigated. The physical properties of these fibres sample. However, that device had problems concerning a are presented in Table 1. HS fibres have substantially fast rate of loading, possible misalignment of fibres, and improved tensile strength whereas their tensile modulus inaccurate gauge-length determination. As suggested then, has not changed greatly. It should be noted that T700S and further modifications were needed to obtain a more con￾T1000 were supplied as epoxy-sized. HM fibres show trolled loading motion and in-situ microscopic observa￾higher tensile modulus in the order of M40J, M50J and tions in order to have accurate sample gauge-length and M60J, but their tensile strength decreases in the same better understanding of the compressive failure behaviour order. As seen from density values in HM fibres, M60J of carbon fibres. presumably has the most crystallite layers packed as a A schematic diagram of the present compression device result of the highest graphitization temperature, thus is shown in Fig. 1. Firstly, a single carbon fibre sample Fig. 1. Compression device for single carbon fibre