Industrial Applications for Titanium Tubing
At the Titanium Europe Conference 2018 held May 15 to 16 in Seville, Spain, Brian Mercer, Director, Tube Products and International Sales & Marketing, for AMETEK Specialty Metal Products, presented a paper entitled “Industrial Applications for Titanium Tubing.”
Representing Fine Tubes, a UK-based unit of AMETEK Specialty Metal Products, Mr. Mercer highlighted the business’ long-standing expertise in the manufacture of high-precision, high-performance titanium alloy tubes for critical applications. Fine Tubes’ seamless titanium tubes are used in aircraft hydraulic systems and chemical processing plants, and for offshore drilling rig components, marine and subsea equipment, and medical implants. Fine Tubes also is a member of the International Titanium Association (ITA), the organising body of the Titanium Europe Conference.
Looking at titanium in comparison to other metals, the following characteristics make it so attractive to multiple industries:
• It’s only 60% as dense as steel-based and nickel-based alloys.
• In alloyed form, its tensile strength is greater than that of austenitic or ferritic stainless steels.
• It is exceptionally corrosion resistant, exceeding the resistance of stainless steels in most environments.
• It is non-magnetic.
• It has excellent heat transfer properties, with a melting point higher than steel alloys.
• It is cold workable.
Hence, it should be no surprise, that titanium is cost effective across a wide range of applications.
As a niche, high-specification manufacturer, Fine Tubes produces straight and seamless tubes in Ti CP (Commercially Pure), Grades 1 and 2, and Grades 5 and 9 alloys, Ti 6Al/4V, and Ti 3Al/2.5V respectively.
Ti 3AI/2.5V alloy is a near alpha, alpha-beta alloy, sometimes referred to as “half-6-4.” It offers 20% to 50% higher tensile strength than CP titanium at room and elevated temperatures and is much more amenable to cold working than Ti 6AI/4V. It also is as heat treatable and weldable as the CP grades, with excellent resistance to torsion and corrosion. With those advantages, Ti 3Al/2.5V is used extensively for tubing in aircraft hydraulic systems and as foil in aircraft honeycomb panels. Other applications include medical and dental implants and sports equipment.
Ti 6Al/4V is the most widely used of all the alpha-beta titanium alloys, accounting for more than 50% of total titanium usage. The alloy is typically used in the annealed condition, at service temperatures through 400°C (750°F). Significantly stronger than CP titanium, Ti 6Al/4V has the same stiffness and thermal properties, excluding thermal conductivity, and is similarly heat treatable. It is typically used in military aircraft engines, turbines, offshore drilling equipment and surgical implants.
From an engineering viewpoint, titanium’s physical characteristics, such as strength-to-weight ratio, biocompatibility, Young’s Modulus (or stiffness) and corrosion resistance, often make it an obvious choice. However, customers generally look for a solution to a specific problem, rather than a metallurgical profile. Convincing the customer that a supplier can deliver that solution requires supportive technical marketing data that explains how that supplier can apply the various needed processes. Those include conditioning, welding, machining, polishing, superplastic forming and more, to convert the raw material -- a specific grade of titanium/titanium alloy -- into a product that will meet the most-challenging engineering applications.
Fine Tubes and Superior Tube, its US-based sister business, have successfully made that case. Significant growth rates in the demand for titanium tubing are projected across an array of markets and applications. These range from hydraulic tubes, which can withstand pressures of up to 5000 psi, to artificial heart valves. Nevertheless, there are potential barriers to growth.
Without further investment in the industry’s productive capability, capacity constraints on the supplier side could lead to unacceptable lead times. Improvements in nickel-based superalloys could challenge titanium’s inherent advantages, as could several other competing materials, technologies and processes. Among those are bar gun-drilling for applications in the medical and offshore industries, carbon fibre for the manufacture of sports equipment, and fly-by-wire in the aerospace sector, to name a few.
That said, the future looks bright for those companies, which continue to invest in the capabilities required to work with titanium and continue as well to listen to, understand and respond to the precise needs of their customers. In aerospace and sports, in water desalination plants, in nuclear power plants, in the chemical processing and in hospitals, the tensile strength, the corrosion resistance, the biocompatibility and the workability of titanium will undoubtedly drive the demand for the foreseeable future.