Mechanical Properties and Microstructural Evolution of Bimetal 1050/Al^sub 2^O^sub 3^/5083 Composites Fabricated by Warm Accumulative Roll Bonding

In this study, a warm accumulative roll bonding process was used to produce a 1050/5% Al^sub 2^O^sub 3^/5083 composite from AA1050 and AA5083 sheets. Firstly, the raw materials were roll-bonded and then rolled up to five accumulative rolling cycles by preheating for 5 min at 280°C before each cycle. The mechanical properties of the ARBed bimetals were evaluated in comparison with 1050/5% Al^sub 2^O^sub 3^ and 5083/5% Al^sub 2^O^sub 3^ roll-bonded single-metal metal matrix composites (MMCs). It was found that two different layers of the bimetal sheet (1050/5% Al^sub 2^O^sub 3^/5083 composite) were deformed in a nearly identical way during the first three cycles. After that, the 5083 layers started necking. The strength of the bimetal samples was superior to the average of these two single-metal MMCs. Furthermore, the strength and ductility of the ARBed bimetal improved by ARB cycles. Finally, the fracture surfaces of the bimetal composite were studied at all ARB cycles by scanning electron microscopy.