Precipitation behavior and microstructural characteristics of hydrogenated β-Ti40 alloys

The effects of hydrogen additions (hydrogen content, CH = 0-0.9 wt.%) on microstructural characteristics and precipitation behavior have been investigated in β-Ti40 titanium alloy of the general composition Ti-25V-15Cr-0.2Si (wt.%). The microstructures were studied using optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that hydrogen addition had a noticeable influence on microstructure of β-Ti alloy. Hydrogen addition decreased the solid solution solubility of Si element leading to the precipitation of Ti5Si3 phase. Effect of hydrogen content on the microstructural model was established.