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

A method for synthesizing an in situ composite based on the A201 aluminum-copper alloy is proposed, utilizing a Self-propagating High-temperature Synthesis (SHS) reaction via the SHSB (Self-propagating High-temperature Synthesis in Bath) process. In this study, a novel synthesis approach is presented, involving a liquid titanium-solid carbon reaction to form titanium carbide (TiC) particles within the A201 alloy, in contrast to the typical solid-solid (Ti-C) reaction. The outcome of this process is the formation of TiC particles, which are primarily located along grain boundaries and contribute to grain refinement, particularly of the (α)Al phase. A focused study of the in situ TiC-reinforced composite was conducted using XRF, optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Vickers microhardness measurements. The present study has a basic research character and focuses on the description of a novel synthesis method for the production of titanium carbides. This reaction proceeds as a solid-liquid type reaction between carbon and titanium. Phase and transmission analyses confirmed the formation of titanium carbides. Furthermore, based on the A201 alloy, the potential for alloy modification was demonstrated, which may inhibit the growth of primary α-aluminum phase grains and thus reduce the susceptibility to hot cracking.