Effects of Cu Addition on Mechanical Behaviour, Microstructural Evolution and Anti-Corrosion Performance of...

Area of Science:

• Materials Science
• Metallurgy
• Corrosion Science

Background:

• Titanium-aluminum (TiAl) intermetallic alloys are crucial for high-temperature applications.
• Understanding the influence of alloying elements on TiAl properties is essential for material design.

Purpose of the Study:

• To investigate the effect of copper (Cu) addition on the mechanical and electrochemical properties of TiAl-based alloys.
• To correlate microstructural changes with observed property variations.

Main Methods:

• Preparation of TiAl alloys with varying Cu concentrations (3-5 at.%).
• Mechanical testing under static (MTS) and dynamic (SHPB) loading.
• Electrochemical testing in Ringer's solution.
• Microstructural analysis using X-ray diffraction (XRD) and optical microscopy (OM).

Main Results:

• Cu addition significantly impacts flow stress and ductility.
• TiAlCu$_{4}$ alloy exhibits increased flow stress, strain rate sensitivity, and fracture strain at higher strain rates.
• The TiAlCu$_{4}$ alloy demonstrates superior anti-corrosion performance.
• Reduced ductility in higher Cu alloys is linked to increased γ phase formation.

Conclusions:

• Copper addition, particularly 4 at.%, optimizes the mechanical properties and corrosion resistance of TiAl alloys.
• The favorable properties of TiAlCu$_{4}$ are attributed to a microstructure with low γ phase and high α$_{2}$ phase content.