Superior Strength and Ductility of In Situ Nano TiB2/Al–Cu–Mg Composites by Cold Rolling and Post-Aging Treatment

Abstract

In this work, the combination of cold rolling with post-aging treatment is developed to achieve the optimal strength–ductility for the in situ nano TiB2/Al–Cu–Mg composite. The microstructure and mechanical properties of the composite subjected to 20% thickness reduction of cold rolling at room temperature and their evolutions upon post-aging at different temperatures were investigated by means of a tensile test, differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy. It was found that the TiB2 particles were effective in dislocation pinning and accumulation during the cold-rolling process. The tensile tests indicated that both the yield and ultimate tensile strengths of the cold-rolling sample increased a lot due to the dislocation strengthening and precipitation strengthening generated by dynamic precipitation during cold rolling in comparison with the conventional T6 sample. After aging at 100 °C/12 h, the elongation to failure reached ~8.4%, which was higher than the conventional T6 sample. Meanwhile, there was also a dramatic increase of strength. The yield and ultimate tensile strengths are ~644 MPa and ~726 MPa, respectively. This remarkable strength–ductility combination was due to the modified microstructure caused prior to artificial aging by the cold-rolling method and the formation of nanosized Guinier–Preston–Bagaryatsky (GPB) zones. The underlying mechanisms related to the superior strength–ductility combination were discussed regarding the microstructural characteristics in the composite.

Microstructure Characteristics and Corrugation Interface Behavior of Al/Mg/Al Composite Plate Rolled Under Large Strain

“…Among them, Al/Mg/ Al composite plates are gradually being widely used in aerospace, rail transit, weapons, equipment, and other fields because of its advantages of lightweight, corrosion resistance, high strength and many complementary advantages of Al and Mg [4,5]. At present, the pressure processing methods for preparing laminated composite plates mainly include rolling [6], extrusion [7], explosive welding [8], high-pressure torsion [9], etc.…”