Microstructures and Phases in Electron Beam Additively Manufactured Ti-Al-Mo-Zr-V/CuAl9Mn2 Alloy.

Area of Science:

• Materials Science
• Metallurgy
• Additive Manufacturing

Background:

• Additive manufacturing enables the creation of novel metal composites.
• Dissimilar metal alloys offer unique property combinations.
• Titanium alloys and copper-aluminum bronzes are critical engineering materials.

Purpose of the Study:

• To investigate the microstructural, phase, and mechanical characteristics of titanium-bronze composites fabricated via electron beam additive manufacturing.
• To understand the effect of varying titanium alloy content on composite properties.
• To analyze wear mechanisms under different alloy compositions.

Main Methods:

• Electron beam additive manufacturing was employed to intermix Ti-Al-Mo-Z-V titanium alloy with CuAl9Mn2 bronze.
• Composites with 5, 10, and 15 vol.% titanium alloy were produced on a stainless steel substrate.
• Microstructural, phase, and mechanical properties, including wear resistance, were analyzed.

Main Results:

• Different microstructures formed based on titanium alloy content (5, 10, 15 vol.%).
• The 5 vol.% alloy exhibited a solid solution, TiCu2Al eutectic, and coarse γ1-Al4Cu9 grains, showing enhanced strength and oxidative wear.
• Higher titanium content (10, 15 vol.%) resulted in Ti(Cu,Al)2 dendrites from γ1-Al4Cu9 decomposition, causing embrittlement and a shift to abrasive wear.

Conclusions:

• The microstructure and mechanical properties of titanium-bronze composites are highly sensitive to the volume fraction of titanium alloy.
• Thermal decomposition of γ1-Al4Cu9 significantly impacts the composite's ductility and wear behavior.
• Electron beam additive manufacturing offers a route to tailor these dissimilar metal composites for specific applications.