An Advanced TiAl Alloy for High-Performance Racing Applications

Area of Science:

• Materials Science
• Metallurgy
• Mechanical Engineering

Background:

• High-performance racing demands innovative lightweight structural materials due to stringent regulations.
• Intermetallic gamma-titanium aluminide (γ-TiAl) alloys present a lower-density alternative to nickel-based superalloys for these applications.

Purpose of the Study:

• To investigate a beta-solidifying TiAl alloy (TNM: Ti-43.5Al-4Nb-1Mo-0.1B at%) for use in racing valves.
• To determine the optimal hot-extrusion parameters for achieving desired microstructures and mechanical properties.

Main Methods:

• Industrial-scale hot-extrusion tests on cast and hot isostatic pressed TNM alloy.
• Hot tensile tests and rotational bending tests at room temperature to simulate operational conditions.
• Scanning electron microscopy (SEM) analysis of fracture surfaces to correlate microstructure with crack initiation.

Main Results:

• Increased degree of hot deformation led to enhanced strength and fatigue limit.
• Significant improvements in ductility were observed with higher deformation levels.
• SEM analysis revealed the relationship between microstructural constituents and crack initiation sites.

Conclusions:

• The mechanical performance of extruded TiAl material is tailorable through optimization of hot-extrusion.
• This study demonstrates the potential of TNM alloy as a viable lightweight structural material for demanding racing applications.