Microstructure and mechanical properties of Ti6Al4V/AA6061/AZ31 laminated metal composites (LMCs) fabricated by hot roll bonding

摘要

In this study, Ti/Al/Mg (Ti6Al4V/AA6061/AZ31) laminated metal composites (LMCs) were fabricated by the hot roll bonding method. The microstructures were observed with scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Tensile tests were conducted to investigate the mechanical properties of the LMCs. The fabricated Ti/Al/Mg LMC samples exhibited satisfactory interfacial bonding. When the annealing temperature was 200 degrees C or higher, intermetallic compounds (IMCs) consisting of Al3Mg2 and Al12Mg17 were observed at the Al/Mg interfaces, whereas no visible interfacial IMCs appeared at the Al/Ti interfaces even after annealing at 400 degrees C. With the increase of annealing temperature, the Ti layers showed similar microstructures, while the grain size of the Al and Mg layers increased. The tensile strength of LMC decreased, while the elongation reached a maximum value at 200 degrees C and then decreased. The thicker IMC layer caused the first fracture of the Ti/Al side when the annealing temperature reached and exceeded 300 degrees C. Compared with the separated Mg sheet, the laminated sheet annealed at 200 degrees C showed optimal comprehensive mechanical properties, with a tensile strength of 415 MPa and an elongation of 19.04%. (C) 2020 Elsevier B.V. All rights reserved.