Beta stabilizing elements and beta titanium alloys

The elements that preferentially dissolve in the β-phase, reduce the homogeneous heterocrystalline transition temperature and expand the β-phase region are β-stabilizing elements, which are classified into β-isocrystalline and β-eutectic types according to the characteristics of their interaction with titanium.

(1) β isocrystalline stabilizing elements are in infinite solid solution with β-titanium, and with the increase of solute elements, they gradually decrease the solid solution of β-isocrystalline elements.

increases, the homogeneous heterocrystalline transition temperature is gradually lowered, there are molybdenum, vanadium, tantalum and niobium.

(2) Eutectic stabilizing elements in addition to lowering the temperature of similar heterocrystalline transformation, but also eutectic transformation. By β-phase eutectic decomposition to form a-phase and intermetallic compounds. According to the difference in the speed of the eutectic reaction can be further divided into two kinds: slow eutectic elements (iron, chromium and manganese); active, eutectic elements (copper, silicon). The speed of eutectic transformation is extremely fast, quenching can not inhibit its progress, so it can not stabilize the β-phase to room temperature.

β titanium alloy is a single-phase alloy composed of β-phase solid solution, not heat-treated that has a high strength, quenching, aging the alloy is further strengthened, room temperature strength up to 1372 ~ 1666MPa; but poor thermal stability, should not be used at high temperatures.