An experimental investigation of fracture toughness, mechanical properties and forming limit curves of Al composites

Abstract

In the present study, accumulative roll bonding is used to fabricate Al base composites with the thickness of 1 mm. then, fracture toughness, mechanical properties and forming limit diagrams (FLD) of them have been investigated versus ARB parameters experimentally. Boron nitride (BN) particles are used as reinforcements and Al/BN composites have been manufactured up to 10 accumulative rolling passes at 300°C. after the 10th pass, the strength of composite samples reached to 168 MPa registering 248% improvement than the initial AA1100 sample. Also, the bonding quality among the composite layers improved by increasing the number of passes. A uniform scattering of Boron nitride particles and bonding strength and quality was improved at higher number of passes. Moreover, the fracture mode at higher passes was observed as shear ductile that had been changed from deep dimples (for low number of passes). The area under the FLDs, dropped sharply after the first pass and then improved at higher passes, as the criterion of formability. Finally, fracture toughness enhanced to the maximum value of 30 MPam1/2 for the composite samples fabricated with 10 passes.