The Temperature Effects on the Mechanical Properties of Pseudo-ductile Thin-ply Unidirectional Carbon-basalt Fibers/Epoxy Hybrid Composites with Different Stacking Sequences

This study aims to investigate the temperature effects on the flexural and Charpy impact behavior of thin-ply unidirectional (UD) carbon-basalt fibers/ epoxy hybrid composites. The hybrid composites with three stacking sequences of thin-ply UD carbon fibers and basalt fibers were fabricated using hand lay-up method. The samples of [CB6C], [B2CB2CB2], and [B3C2B3] were prepared where B and C are respectively related to the basalt fibers and thin-ply UD carbon fibers and the numbers illustrate the number of composite layers. The flexural test results indicated that the flexural strength and modulus of samples decreased by increasing the temperature to 130 ºC. However, the results indicated that the position of the thin-ply UD carbon fibers in the laminates had a considerable effect on the properties. By placing the thin-ply UD carbon fibers at the top and bottom sides, the flexural properties improved and the negative effects of temperature reduced, compared with other stacking sequences. The reduction percent in flexural strength of [CB6C], [B2CB2CB2] and, [B3C2B3] were respectively about 4.62%, 8.82%, and 7.73% at temperature of 95 ºC. Besides, the temperature and position of the thin-ply UD carbon fibers had major effects on the pseudo-ductile strain of samples. The pseudo-ductile strain of samples increased by placing the thin-ply UD carbon fibers in the center of samples. At a temperature of 95 ºC, the pseudo-ductile strain value of [B3C2B3] sample was respectively about 2 and 6 times higher than that of [CB6C], and [B2CB2CB2] samples. On the other hand, pseudo-ductile strain increased by increasing the temperature up to a certain value. Also, the Charpy impact test results showed a decrease in the absorbed energy values by increasing the temperature. However, the [B2CB2CB2] sample had the higher absorbed energy values due to the occurrence of more delamination.