Aerospace Titanium: ATI Technologies Ltd

ATI Technologies Ltd is a specialist stockist, manufacturer and distributor of Titanium, Cobalt Chrome and Zirconium alloys.

Having been established for more than 30 years, ATI Technologies offers extensive stocks of high quality titanium alloy bars, titanium wire, titanium sheet, plate, titanium tube, pipe and forging stock certified to British, American and European specifications. They serve a full range of markets including biomedical, aerospace, chemical processing plant, oil, metal finishing, jewellery and motor sport.

ATI Technologies has a 4,000 square metre service centre located in Birmingham where it offers a full in-house precision plate cutting, bar cutting and guillotining service. In addition to their conventional plate sawing facilities the company are also able to offer engineered shapes through the use of their state of the art in-house waterjet cutting facility.

Non-standard sizes, open die forgings and castings can be manufactured to order and experienced titanium metallurgists and engineers are available on site to provide customer support and technical back-up.

ATI Technologies operates an ISO 9001 quality management system and is an approved supplier to many of the world’s major orthopaedic device manufacturers.

The aerospace industry is the single largest market for titanium products primarily due to the exceptional strength to weight ratio, elevated temperature performance and corrosion resistance. Titanium applications are most significant in jet engine and airframe components that are subject to temperatures up to 1100° F and for other critical structural parts. Usage is widespread in most commercial and military aircraft. Titanium is also used in spacecraft where the many benefits of titanium are effectively utilized.

As new titanium products, alloys and manufacturing methods are employed by the aircraft industry, the use of titanium will expand. Today the use of precision castings and new alloys such as and Ti-3AL8V-6Cr-4Zr-4Mo are making it possible for titanium to displace alternate, less efficient structural materials in a wide spectrum of aerospace applications.

Lockheed engineers stated that while only titanium and steel had the ability to withstand the operating temperatures encountered, aged Ti-13V-11 Cr-3AL titanium weighed one-half as much as stainless steel per cubic inch and its ultimate strength was about equal to stainless. Using "conventional" fabrication techniques, fewer parts were needed with Ti-13V-11 Cr-3AL than with steel.

Engines: The largest single use of titanium is in the aircraft gas turbine engine. In most modern jet engines, titanium-based alloy parts make up 20% to 30% of the dry weight, primarily in the compressor. Applications include blades, discs or hubs, inlet guide vanes and cases. Titanium is most commonly the material of choice for engine parts that operate up to 1100°F (593°C.).

Airframes: Titanium alloys effectively compete with aluminum, nickel and ferrous alloys in both commercial and military airframes.

Applications run the gamut of airframe structural members; from massive, highly stressed, forged wing structures, and landing gear components, to small critical fasteners, springs, and hydraulic tubing.

Selection of titanium in both airframes and engines is based upon titanium's basic attributes; weight reduction due to high strength to weight ratios coupled with exemplary reliability in service, attributable to outstanding corrosion resistance compared to alternate structural metals.

F-22 Raptor

Space structures starting with the extensive use of titanium in the early Mercury and Apollo space craft, titanium alloys continue to be widely used in military and NASA space applications. In addition to manned space craft, titanium alloys are extensively employed in solid rocket booster cases, guidance control pressure vessels and a wide variety of applications demanding light weight and reliability.

Thick Section Titanium or Heavy Section size is generally defined as forged or rolled thickness that exceeds four inches. Titanium alloys have been successfully used for heavy sections thickness, in both airframe parts, and in rotating components such as heavy section fan disks for PWA and G.E. high bypass jet engines, and Sikorsky helicopter rotor forgings.

The primary alloys that have been involved are Ti-6AL-4V, in the annealed or STOA (Solution Treated and Overaged) condition; the near-beta Ti-17 (Ti-5AL2Sn-2Zr-4Mo-4Cr), Ti-10V-2Fe-3AL and the Ti-6AL-2Sn-4Zr-6Mo compositions in the STA (Solution Treated Aged) condition; and the beta alloys Ti-13V-11 Cr-3AL and Ti-3AL-8V-6Cr-4Mo-4Zr, also in the STA condition. Certainly the most extensive heavy section applications in one project to date featured the Ti-1 3V-11 Cr3AL alloy in the SR-71 Blackbird (fuselage frames, wing beams and landing gears).

For a given process and heat treatment condition, titanium alloys such as these demonstrate superior fatigue and fracture toughness properties, not only in the absolute sense, but also from the standpoint of uniformity throughout the heavy section thickness, and as the section thickness increases from 4" to 6", or even to 8". Titanium alloys offer a useful and, in many cases, superior alternative to steel alloys for heavy section application.