Formation of intermetallic compounds and their effect on mechanical properties of aluminum–titanium alloy films

Abstract

AbstractAl–Ti alloy films with various Ti contents were prepared through magnetron co-sputtering with Al and Ti targets and treated with vacuum annealing at 400 °C. Energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and nanoindentation were used to determine the composition, microstructure and hardness of the films to reveal the existence of intermetallic compounds and their effects on the microstructure and mechanical properties. The results showed that Al–Ti films with lower Ti contents formed nanocrystalline structures of highly supersaturated solid solution. With the increase of Ti content, various types of Al–Ti intermetallic compound bonds formed. The existence and increasing concentration of these compound bonds gradually transformed the films into amorphous structures and supported the continual increase of the film hardness, reaching a high value of 8.8 GPa at 36.3 at.% Ti.