Effects of Rolling Deformation on the Microstructure and Properties of GNPs/2024Al Composite Materials

Abstract

This study investigates the effects of rolling deformation on the microstructure and properties of graphene nanosheet-reinforced 2024 aluminum matrix composites (GNP/2024Al composites). The investigation involved several tests, including microhardness tests, intergranular corrosion performance tests, metallographic analysis, and electrochemical analysis. The results reveal that rolling deformation alters the microstructure of GNP/2024Al composites. Specifically, increasing rolling deformation leads to the distribution of grains along the rolling direction, the aspect ratio becomes larger, and the grain becomes slender. At 20% rolling deformation, the composite’s hardness improves, but at 40 and 55% deformation, the hardness decreases slightly. However, the overall range of hardness changes is small. As the deformation increases, the fibrous structure becomes more slender, leading to more grain boundaries per unit area. Additionally, the hot rolling process presses some microstructural defects that affect corrosion together, reducing such defects in the microstructure. The corrosion current density of the GNP/2024Al composites initially increases and then decreases with increasing rolling deformation, while the intergranular corrosion resistance decreases and then increases. Finally, the microscopic mechanism behind these observations is discussed.