Interfacial evolution and bonding mechanisms inγ-TiAl/Al explosive welding: a molecular dynamics study

Area of Science:

• Materials Science
• Metallurgy
• Computational Materials Science

Background:

• Explosive welding (EXW) is a promising technique for fabricating lightweight, high-strength hybrid structures using γ-TiAl and Al.
• Understanding the atomic-scale bonding mechanisms in γ-TiAl/Al EXW is crucial for process optimization.

Purpose of the Study:

• To investigate the effects of flyer velocity and collision angle on the thermal response, diffusion, phase evolution, and mechanical properties of γ-TiAl/Al EXW.
• To elucidate the fundamental atomic processes governing γ-TiAl/Al EXW.

Main Methods:

• Large-scale molecular dynamics simulations were employed.
• Simulations explored flyer velocities from 1.5 to 2.9 km s⁻¹ and collision angles from 10° to 40°.
• Analysis included thermal response, diffusion, phase evolution, and mechanical performance.

Main Results:

• Increasing flyer velocity promotes transitions from solid-solid to liquid-liquid mixing, raising interfacial temperature and diffusion layer thickness.
• Optimal strength-ductility balance was achieved at a flyer velocity of 2.5 km s⁻¹ with a well-mixed interface.
• Collision angles up to 30° improved joint strength and ductility, while 40° led to shear-driven separation.

Conclusions:

• The study provides fundamental insights into the atomic mechanisms of γ-TiAl/Al EXW.
• Findings offer quantitative guidance for optimizing processing parameters to enhance lightweight structural applications.