Investigation of metal-matrix composite based hybrid laminates under quasi-static penetration and Charpy impact loading

Abstract

The primary objective of the research presented here is to investigate the mechanical properties of SiCp/AA6061 based, directly-bonded hybrid laminates (HLs). Hot-pressing technique is introduced to manufacture polymer/metal/polymer HLs. Two types of thermoplastic composites (TPCs) are stacked with the metal-matrix composite (MMC). Long glass fiber-reinforced polypropylene (PP) composite sheets (20 wt% and 40 wt%) are placed in the front of and rear of the MMC plates. In this way, the effect of PP composites with different fiber amounts on perforation and Charpy impact behavior is evaluated. Failure mechanisms of the HLs are also scrutinized. The experimental results show that the HLs result in improved mechanical properties. Enhancement of the maximum penetration force is more pronounced in the HLs struck from the TPC-40. The absorbed energy in the quasi-static perforation tests is found to be up to 12.24 and 23.59 times higher compared to monolithic TPC-20 and TPC-40, respectively. The images of the damaged HLs demonstrate the plugging shear out and fiber pullout at the strike and rear faces, respectively. The MMC-based HLs also lead to the increase in the impact resistance. By replacing the blow surface from TPC-20 to TPC-40, the flatwise Charpy impact strength significantly improves from 122 kJ/m 2 to 137.11 kJ/m 2 . The scanning electron microscopy (SEM) investigations after the impact experiments support that the fiber fracture is the dominant mechanism for failure mode of the faces under impact. Besides, signs of ductile fracture are seen for the MMC layer.