A Complete Study of MAX Phases Ti₃Si_1–<i>x</i>Cu_<i>x</i>C₂ (0 ≤ <i>x</i> ≤ 1) Formation: Ab Initio Calculations and Sustainable Synthesis

Using density functional theory calculations, we simulated the substitution of silicon by copper in Ti3SiC2 with the formation of Ti3Si1–xCuxC2 (x = 0.0; 0.125; 0.25; 0.5; 0.75; 0.875; 1.0). We found that the Si–Cu substitution was possible up to half, with the formation of Ti3Si0.5Cu0.5C2. The elastic matrices for Ti3SiC2, Ti3Si0.5Cu0.5C2, and Ti3CuC2 were calculated to determine the effect of substitution on the mechanical properties of the materials. It has been confirmed that the presence of copper leads to a decrease in elastic moduli and an increase in thermal resistivity. In this regard, Ti3Si0.5Cu0.5C2 may be a promising thermal barrier coating material with a thermal conductivity of about 1.6 W m–1K–1. According to the electronic structure, both compounds have zero band gaps. In addition, an attempt to synthesize the Ti3Si1–xCuxC2 material was carried out using high-temperature self-propagating synthesis. As a result, a sample with more than 70% yield of Ti3SiC2 content was obtained through rapid and environmentally friendly synthesis, and then a 20% yield of Ti3Si0.929Cu0.071C2 composition was achieved, which was confirmed by the X-ray diffraction and energy-dispersive X-ray spectroscopy investigations.