Main page
About us
Sliding Bearings Consulting
Advertising Opportunities
to Metals
to Titanium alloys
Dr. Dmitri Kopeliovich
Titanium β-alloys are titanium alloys rich of β-phase due to the presence of substation amount of β-phase stabilizers: molybdenum (Mo), vanadium (V), tungsten (W), tantalum (Ta), silicon (Si). β-phase stabilizers prevent β-α transformation at high cooling rates of [Basic principles of heat treatment#Hardening|quenching]].
Content of α-phase stabilizers (aluminum) in titanium β–alloys is lower, than in α- and α-β alloys.
Titanium β-alloys are heat-treatable. They may be significantly strengthened by precipitation hardening. Solution treatment of β-alloys causes transformation of α-phase, which is stable at room temperature, to β-phase, which is stable at temperatures above the Beta Transus. Quenching suppresses β-α transformation.
The metastable β-phase partially transforms to fine precipitation particles of α-phase during aging.
The precipitation treatment results in increase of mechanical strength and decrease of ductility.
Titanium β-alloys, containing at least 10% of chromium (Cr), possess increased burn resistance and are used in aircraft engines at temperatures up to 950ºF (510ºC).
β –alloys are heat-treatable to very high strength and have good hot formability.
Ductility and fatigue strength of the alloys in heat-treated conditions are low.
Titanium β-alloys are normally supplied in solution-treated condition.
Titanium β-alloys are used for manufacturing aerospace components, high-strength fasteners, torsion bars, high-strength aircraft sheets, burn-resistant aircraft engine parts.
Designation | O,% | V,% | Fe,% | Al,% | Mo,% | Cr,% |
---|---|---|---|---|---|---|
Ti-10V-2Fe-3Al | 0.13 max. | 9-11 | 1.6-2.2 | 2.6-3.4 | - | - |
Ti-15V-3Cr-3Sn-3Al | 0.13 max. | 14-16 | 0.3 max. | 2.5-3.5 | - | 2.5-3.5 |
Ti-4.5Fe-6.8Mo-1.5Al | 0.15 | - | 4.5 | 1.5 | 6.8 | - |
(Concentration of nickel - balance)