Effects of extended soaking time preceding roll bonding on the microstructure and mechanical properties of a modified AA3003 cladded with AA4045

The effect of the extended soaking period in hours on the microstructure and mechanical properties of a modified AA3003mod cladded with AA4045 for use in automobile heat exchangers investigated. The alloys were roll bonded to have a final thickness of 300 μm. Intermediate annealing (IA) was conducted during cold rolling at temperatures of between 270 and 350 °C. The microstructures were investigated by using electron backscattered diffraction (EBSD). The fractographs of tensile-test specimens were analysed using the SEM-SEI. The UTS and YS of the samples soaked for longer residence times of 45 h, were found to be on the lower end of the 9031-H24 specification. Extended soaking time increased Al-Mn-Fe intermetallic phases observed on fracture surfaces, which degraded the yield strength (Rp0.2) by 35 MPa.