Electrodeposition of titanium aluminides from aluminum chloride: 1-butyl-3-methyl imidazolium chloride ionic liquid
The key for achieving sustainable future depends not only on the discovery of new advanced structural materials, but also on the development of novel energy-efficient technologies for their production and processing in industries. Titanium aluminides are new emerging class of high-temperature structural materials that show promising application in aerospace and automotive industries. Because of their unique properties like low weight, high strength, good oxidative and creep resistance, titanium aluminides are increasingly finding their way to replace steel as structural materials. Compared to the existing industrial techniques, electrodeposition of titanium aluminides in ionic liquid electrolytes is an attractive process because of its low cost, low temperature, good current efficiency, and low energy consumption. In the present study, electrodeposition of titanium aluminides from aluminum chloride-1-butyl-3-methylimidazolium chloride (2:1 mole ratio) electrolyte was investigated at 100 °C. Chronopotentiometric experiments were conducted at different current densities (135 to 891 A/m2) for 4 h. Dissolution of titanium anode into the melt and electrodeposition of TiAl alloys onto titanium cathode took place at different current densities. Surface morphology and compositional analysis of TiAl alloys were examined using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) methods. The morphology of TiAl alloy deposits changed from dendritic to granular shape at higher current densities. XRD and EDS analysis have confirmed the presence of disordered face-centered cubic (FCC) lattice in high pure TiAl alloys. The TiAl electrodeposits containing 14.56 to 20.75 atom% Ti were produced with current efficiencies of 60.96 - 81.35% and energy consumptions of 6.71 - 12.08 kWh/kg.