The effects of strain path change on the microstructure, texture, and mechanical properties of accumulative roll-bonded (ARBed) AA1050 strips

In this study, the effect of unidirectional accumulative roll bonding (UARB) and rotational ARB (RARB) on the microstructure, texture, and mechanical properties of AA1050 sheets was investigated. The X-ray diffraction technique was used to study the microstructural and textural evolutions in the processed samples. It was found that the successive sample rotation suppressed the evolution of low-angle grain boundaries (LAGBs) to high-angle ones in the RARBed sheets. However, the grain size was dramatically reduced from 35.7 μm to 169 nm in the starting Al and the processed sample by eight RARB cycles, respectively. Akin to the UARB path, the RARB route led to a drastic drop in Cube {001} <100> texture intensity. Compared to the UARBed strips, additional Goss {011} <100>, A {011} <111>, P {011} <122> and BR {236} <385> components were observed in the RARB-processed sheets. Interestingly, the rotation of Goss-oriented grains towards the Brass {011} <211> component was frustrated by consecutive sample rotation around its normal direction (ND) between RARB passes. In addition to the microhardness test, the uniaxial tensile test was performed at room temperature to evaluate the mechanical properties of the processed aluminum. The results showed that a sharp increase in hardness reached a plateau at higher cycles. In terms of tensile properties, the ultimate tensile strength (UTS) increased to its peak of 332 MPa after eight cycles of the RARB method. Although, their lower interlayer bond strength gave them low elongation compared to their UARBed counterparts.