Synthesis of an Intermetallic Alloy Based on 2Cu–Ti–Al: Structure Analysis and Electrophysical Properties

An intermetallic alloy based on the Heusler phase—Cu2TiAl—has been obtained by self-propagating high-temperature synthesis (SHS) in the Cu–Ti–Al system for the first time. The modes of frontal combustion of the green mixtures and the processes of phase formation during synthesis have been studied. The resulting products have been studied by X-ray analysis (including high-temperature diffractometry with step heating up to 900 K), scanning electron microscopy, and differential thermal analysis (DTA), and some physical properties have been studied. Electrophysical and magnetic measurements are also carried out for the alloy. The results of X-ray analysis and scanning electron microscopy using energy-dispersive analysis (EDA) have shown that the content of the Heusler phase in the synthesized product is at least 82%. The product also contains copper (CunineAl4) and titanium (Ti3Al2) aluminides. The temperature dependence of the electrical resistivity of the synthesized product is measured for a wide temperature range of 90–1000 K. The resistivity at T = 300 K is 0.3 μm Ωm. The metallic type of conductivity for obtained samples and the anomalous behavior of the temperature curve of electrical resistance in the region of 770–790 K are revealed. Thermal analysis is used to measure the melting point of the synthesized product and reveal additional heat effects at 788, 848, and 1248 K associated with possible phase transitions in the Cu2TiAl intermetallic compound. One possible mechanism of these phase transitions is considered in accordance with the phase diagram of the Cu–Ti–Al system. Magnetic measurement results show that intermetallic samples of the compound obtained by the SHS method exhibit weak ferromagnetic properties with residual magnetization of 0.069 A m2/kg.