Addressing Oxygen Embrittlement in Additively Manufactured Titanium via Cu-Mediated Interstitial Site Engineering

Area of Science:

• Materials Science
• Metallurgy
• Physical Chemistry

Background:

• The strength-ductility balance in titanium alloys is often compromised by interstitial oxygen.
• Octahedral oxygen (oct-O) typically causes embrittlement, limiting alloy performance.

Purpose of the Study:

• To redefine the role of oxygen in titanium alloys by stabilizing alternative oxygen configurations.
• To achieve an unprecedented strength-ductility synergy in titanium alloys.

Main Methods:

• Controlled laser powder bed fusion (L-PBF) processing.
• Cu-O co-alloying to thermodynamically stabilize hexahedral oxygen (hex-O).
• Investigating Cu-induced charge redistribution and rapid solidification effects.

Main Results:

• Successfully stabilized hexahedral oxygen (hex-O) configurations, mitigating embrittlement.
• Demonstrated hex-O enhances -component dislocation activity and strain hardening.
• Achieved a yield strength of 1121 MPa and a fracture elongation of 10.2%.

Conclusions:

• Interstitial engineering of oxygen offers a new pathway for tailoring titanium alloy properties.
• Stabilizing hex-O via Cu co-alloying and L-PBF overcomes traditional strength-ductility limitations.
• This work presents a novel method for developing high-performance oxygen-tolerant titanium alloys.