Types of Titanium Alloys

Types of Titanium Alloys

Titanium is considered to be one of the strongest metals. Its strength, heat, water and salt resistance, and its light weight make it the ideal metal for a variety of applications. These applications range from jewelry and dental implants to airplanes and ships. Pure titanium is strong and corrosive resistant. Titanium alloys retain the same strength and corrosion resistance, but takes on the greater flexibility and malleability of the metal it is combined with. Titanium alloys, therefore, have more applications than pure titanium. There are six grades of pure titanium (grades 1,2,3,4,7 and 11) and 4 varieties of titanium alloys. Titanium alloys typically contain traces of aluminum, molybdenum, vanadium, niobium, tantalum, zirconium, manganese, iron, chromium, cobalt, nickel, and copper.

The four grades, or varieties of titanium alloys are Ti 6AL-4V, Ti 6AL ELI, Ti 3Al 2.5 and Ti 5Al-2.5Sn.

Ti 6Al-4V (Grade 5)

Ti-6AL-4V is the most commonly used of the titanium alloys. It is therefore commonly referred to as the titanium alloy “workhorse.” It is believed to be used in half of the usage of titanium around the world.

These desirable properties make Ti-6AL-4V a popular choice in several industries including medical, marine, aerospace and chemical processing. Ti 6AL-4V is commonly used to make:

Aircraft turbines

Engine components

Aircraft structural components

Aerospace fasteners

High-performance automatic parts

Marine applications

Sports equipment

Ti 6AL-4V ELI (Grade 23)

Ti 6 AL-4V ELI is commonly referred to surgical titanium because of its use in surgery. It is a more pure version of Grade 5 (Ti 6AL-4V) titanium alloy. It can be easily molded, and cut into small strands, coils, and wires.

It has the same strength, and high corrosion resistance as Ti 6AL-4V. It is also light-weight and is highly tolerant to damage by other alloys. Its use is highly desirable in the medical and dental fields for uses in complex surgical procedures not only because of these properties but also because of the unique surgical properties Ti 6AL-4V ELI has. It has superior biocompatibility making it easy to graft in and attach to bone all the while being accepted by the human body. Some of the more common surgical procedures Ti 6AL-4V ELI is used in include:

Orthopedic pins and screws

Orthopedic cables

Ligature clips

Surgical staples

Springs

Orthodontic appliances

In joint replacements

Cryogenic vessels

Bone fixation devices

Ti 3Al 2.5V (Grade 9)

Ti 3 Al 2.5V is the titanium alloy with the best weldability. It is also strong at high temperatures like the other titanium alloys. This grade 9 titanium alloy is unique in that it exhibits characteristics of stainless steel (one of the other strong metals), such as being heavier than the other titanium alloys.

Ti 3 Al 2.5V is most commonly used in the manufacturing industry, specifically in equipment. It is highly resistant to corrosion and can be formed by heat or cold. Grade 9 titanium alloy is used the most in the following industries and applications:

Shell and heat exchangers

Hydrometallurgical applications

Elevated temperature chemical manufacturing

Marine and airfare components

Titanium as a whole is a highly durable and strong metal. In its pure form it has many uses. It alloys add greater malleability and flexibility to the already strong metal, opening up doors to many more applications. Each titanium alloy shares the same strength and corrosion resistance. They vary on flexibility, making a specific alloy ideal for specific industries and applications.