Achieving strong and ductile as-printed Ti-Cu alloys via tailoring eutectoid morphology

Abstract

The addition of Cu into Ti alloys forms brittle eutectoid lamellae and severely deteriorates ductility although it enhances strength and eliminates columnar grains during laser powder bed fusion process. This study reveals that the deformation behavior of as-printed Ti-Cu alloys depends on eutectoid morphology, with a ductile-to-brittle transition occurring once eutectoid Ti2Cu lamellae form. Reducing laser energy density facilitates the morphological transition of Ti2Cu from lamellar to granular. A Ti-5.0Cu alloy characterized by equiaxed prior-β grains and discontinuous Ti2Cu particles exhibited considerable tensile properties, with an ultimate tensile strength of 1198 MPa and an elongation of 6.5%.

Keywords

• Laser powder bed fusion
• titanium alloys
• powder processing