Microstructural evolution, mechanical properties, and corrosion behavior of hot-rolled Ti-Zr-Al-Sn alloys

A systematic study was conducted on the microstructure, mechanical properties, and corrosion resistance of Ti-20Zr-xAl-2.5Sn (x = 5, 7, 9, 11, and 13 wt.%) quaternary alloy. The microstructure of the rolled alloys was characterized by optical microscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The mechanical properties were analyzed through tensile tests, microhardness tests, and friction wear tests. Corrosion performance was evaluated using electrochemical tests, and X-ray photoelectron spectroscopy was employed to analyze the passivation film on the alloy surface. The results show that increasing Al content improves the mechanical properties of the alloy, but excessive Al leads to the creation of Ti₃Al, resulting in a substantial deterioration of the mechanical characteristics of the alloy. The alloy with 7 wt.% Al exhibited the best overall mechanical properties. Electrochemical experiments revealed that higher Al content positively affected the corrosion resistance, with the alloy containing 7 wt.% Al showing the best corrosion resistance, followed by a slight decline. A small amount of Al₂O₃ in the passivation film enhanced the corrosion resistance, but the formation of Al₂O₃ with higher Al content decreased the corrosion performance.