In the aerospace sector vanadium ensures the low density, high strength and ability to maintain strength at high operating temperatures essential for materials used in many applications such aero-engine gas turbines and in airframes.
A titanium alloy containing 4% vanadium and 6% aluminium (Ti6Al4V) has been used very extensively for blades, discs and casings of the compressors in many designs of the aero-engine gas turbine. The heat treatment made possible by the vanadium and aluminium enables high strength alloys to be produced that maintain a high strength up to temperatures of the order of 545°C. The high strength of this alloy has also enabled it to be used for highly stressed parts of airframes and undercarriages.
High strength and retention of strength at high temperatures for prolonged periods, are essential in materials selected for all sections of gas turbines used in aircraft. Vanadium is added to steels to give high strength and creep resistance at temperatures above 550ºC. Examples of these steels include chromium-molybdenum steels for turbine shafts and high chromium corrosion resisting steels for rotor discs. Also, the bearings for aero-engine gas turbines are frequently made from steel containing 1% vanadium with 18% tungsten and 4% chromium. This type of steel, originally designed for high sped machining tools, contains primary and secondary vanadium carbides which are stable up to at least 550°C, and provides the wear resistance required to meet the arduous conditions of bearings carrying rotor shafts rotating at high speeds at temperatures in excess of 500°C.
Ultra-high strength steels containing vanadium are widely used for aircraft undercarriage components. The most widely used steel for this application is 300M, which is a medium carbon vacuum melted NiCrMo steel containing up to 0.1%V, and
Development of new titanium alloys continues and grades containing 8, 10 and 15% vanadium have even higher strengths and have the potential to make important contributions to weight reduction and fuel efficiency in aircraft of the future.
8% vanadium alloys possess high strength and high flexibility so that the lighter titanium alloys can now replace steel for springs.
10% vanadium alloy in the form of heat treated forgings is used in airframes particularly for the support structures in undercarriages and has been successfully applied in the Boeing 777.
15% vanadium alloy is produced as sheet with cold working properties and has a potential for air ducting in aircraft.