Work

Effect of Ti on microstructure and mechanical properties of high strength AA6xxx alloy

Year: 2025

Type: article

Abstract: • Effect of Ti on AA6xxx alloy is traced from direct-chill casting to extrusion. • Increased liquidus and Zr/Si facilitate Al 3 Ti-(Al,Si) 3 (Ti,Zr) core–shell particles. • (Al,Si) 3 (Ti,Zr) shell has lower nanohardness and elastic modulus than Al 3 Ti core. • Bending is affected more by Fe-rich particles and peripheral coarse grain zone. Titanium is common in recycled aluminium alloys but limited in high-strength variants containing Zr and Cr. This study shows that Ti increases the liquidus temperature and promotes the formation of Al 3 Ti-(Al,Si) 3 (Ti,Zr) core–shell intermetallics. Zr and Si absorption reduces hardness and enhances the plasticity of Al 3 Ti intermetallic. Ti addition improved extruded profile bending performance due to a reduced peripheral coarse grain depth, while cracks propagated via voids at Fe-intermetallics rather than Ti-intermetallics.

Source: Materials Letters

DOI: 10.1016/j.matlet.2025.138280