Effect of zirconium content on the microstructure, physical properties and corrosion behavior of Ti alloys

A series of Ti-xZr alloys with Zr contents ranging from 5 to 20 wt% was prepared and the effects of Zr addition on the microstructure, physical properties, and corrosion behavior of Ti alloys were investigated. The phase and microstructures were characterized using X-ray diffractometry (XRD), optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The Ti-xZr alloys exhibited α-Ti structure at Zr content of 20 wt% or below. Commercially pure titanium (cp-Ti) was used as a control. We also investigated the effects of alloying element Zr on the mechanical property, oxidation protection ability, and corrosion behavior of Ti-xZr binary alloys. The physical properties and corrosion behavior of Ti-xZr alloys were sensitive to the Zr content. The addition of Zr did contribute to the hardening of cp-Ti due to solid-solution strengthening of α-Ti. Ti-xZr alloys containing up to 10 wt% Zr resulted in good oxidation resistance, while Ti-xZr alloys with above 10 wt% Zr demonstrated higher oxidation weight gain than cp-Ti. Electrochemical experiments showed that the Ti-xZr alloys exhibited better corrosion resistance compared to that of cp-Ti.