Fabrication of Functionally Graded Aluminum Sheets with a Gradient of Grain Size Through the Efficient Combination of Severe Plastic Deformation Techniques

Abstract

In this research, a novel single-phase functionally graded material based on 1050 aluminum was fabricated through an innovative approach using accumulative roll bonding. Unlike conventional FGM manufacturing techniques that often involve multi-phase compositions or complex processing routes, the proposed method introduces a unique microstructural gradient along the transverse direction solely by controlled ARB passes. This strategy enables the creation of a continuous grain size gradient without the addition of reinforcements or secondary phases, ensuring both structural integrity and cost-effectiveness. X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) were utilized for structural and microstructural studies, respectively. The XRD results indicated that as the number of rolling cycles through the thickness of the functionally graded sample increases, the crystallite size decreases and dislocation density increases. Also, the EBSD maps confirmed a gradient in grain size across the functionally graded sample's thickness from 1060 nm to 290 nm. The resulting FGM exhibited improved mechanical performance, with yield and tensile strengths of 167 MPa and 246 MPa, respectively. This study introduces a simple, cost-effective route for producing aluminum-based FGMs with tailored microstructural gradients.