Metal composites produced through the liquid metal dealloying (LMD) process feature an advanced matrix-matrix composite structure, where two metallic materials form a continuous, three-dimensional interconnected network. This study investigates the effects of TiCu precursor compositions on dealloying behavior and microstructural evolution in liquid Mg, using Ti₅₀Cu₅₀ and Ti₃₀Cu₇₀ precursors. The initial microstructure of the precursor significantly influences dealloying kinetics and phase transitions. The single-phase Ti₅₀Cu₅₀ precursor exhibits a faster initial dealloying rate due to its homogeneous structure, yet complete dealloying requires 90 min. In contrast, the dual-phase Ti₃₀Cu₇₀ precursor achieves complete dealloying in 30 min, demonstrating the impact of a higher Cu concentration on accelerating the process kinetics. Additionally, the study explores the coarsening behavior and hardness variations during the LMD process, along with the microstructural characteristics of Mg-Ti composites fabricated from these two precursors. The findings highlight the critical role of precursor composition in tailoring the microstructure and properties of Mg-Ti composites produced through the LMD process, demonstrating its potential for advanced composite material manufacturing.

This study presents a novel process for the fabrication of metal–intermetallic composites with a 3D bicontinuous structure, achieved through a combination of liquid metal dealloying (LMD) and subsequent alloying. Initially, porous Ti structures are produced using the LMD process, followed by immersion in a molten Mg–3Al (wt%) metal. Due to the higher thermodynamic miscibility of Al with Ti compared to Mg, the concentration of Al in the Ti matrix increases as the immersion time increases. This results in a sequential phase transition within the Ti matrix: α-Ti → Ti₃Al → TiAl. The phase transition considerably affects the hardness and strength of the composite material, with the Mg–Ti₃Al–TiAl composite exhibiting a maximum hardness nearly twice as high as that of the conventional Mg–Ti composite. This innovative process holds potential for the development of various bicontinuous metal–intermetallic composites.