Interlaminar shear strength of fibre metal laminates after thermal cycles

Fibre Metal Laminates are characterized by low density, high static and fatigue strength, high impact resistance and good corrosion resistance. Currently some new solutions of FML which will contain carbon fibre reinforced polymer layers with aluminium (CARALL laminates) are tested. The purpose of the study was to investigate the influence of the thermal cycles on interlaminar shear strength and microstructure of aluminium-carbon fibres laminates modified by additional glass interlayer. Six different variants of laminates were tested. The 1500 thermal cycles were used. Before and after thermal cycles, the Interlaminar Shear Strength tests were conducted to compare the shear properties of CARALL and CARALL with thin glass interlayer. No delamination, cracks of matrix or fibres were observed after thermal cycles. The interlaminar shear tests have shown that the strength is not dependent on thermal cycles. However, some differences in microstructure of FML after ILSS were noted. Laminates without thermal cycles were damaged more often by delamination at the metal/composite interphases in the middle region of sample (directly under the stamp), whilst the laminates after thermal cycles were damaged also by delamination at the metal/composite interphases but the delamination mostly originated from the edges of the samples. National Science Centre, Poland UMO-2014/15/B/ST8/03447.