Microstructural Evolution of Al-Cu/TiC In Situ Composites via Solid-Liquid Titanium-Carbon Reactions.

Area of Science:

• Materials Science
• Metallurgical Engineering
• Composite Materials Synthesis

Background:

• In situ composite synthesis offers advantages over traditional methods.
• Aluminum-copper alloys like A201 are widely used but can be susceptible to hot cracking.
• Titanium carbide (TiC) is a known reinforcement material for metal matrix composites.

Purpose of the Study:

• To develop a novel synthesis method for in situ titanium carbide (TiC) reinforced A201 aluminum-copper alloy composites.
• To investigate a liquid titanium-solid carbon reaction for TiC formation, differing from conventional solid-solid reactions.
• To evaluate the microstructural effects and potential benefits of TiC reinforcement in the A201 alloy.

Main Methods:

• Self-propagating High-temperature Synthesis in Bath (SHSB) process utilizing a liquid-solid reaction.
• Characterization using X-ray fluorescence (XRF), optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Vickers microhardness testing.
• Analysis of TiC particle formation, distribution, and effect on the aluminum matrix microstructure.

Main Results:

• Successful synthesis of titanium carbide (TiC) particles within the A201 aluminum alloy matrix via a novel liquid-solid reaction.
• TiC particles were predominantly observed along grain boundaries, leading to significant grain refinement of the primary α-aluminum phase.
• Microstructural analysis confirmed the formation of titanium carbides and demonstrated their influence on grain growth inhibition.

Conclusions:

• The developed SHSB method provides an effective route for producing in situ TiC reinforced A201 aluminum alloy composites.
• The in situ formed TiC particles contribute to grain refinement and show potential for reducing the hot cracking susceptibility of the A201 alloy.
• This novel synthesis approach opens possibilities for advanced alloy modification and the development of high-performance aluminum matrix composites.