Titanium is renowned for its strength, light weight, and resistance to heat, water, chemicals, corrosion, and other stresses that harm the integrity of many common metals. From jewelry and dental implants to drive shafts and turbine blades, designers, engineers, and manufacturers find titanium to be an ideal material for many of their products. It can be challenging to determine the right type for a specific application because there are so many different types of titanium. The information provided below is intended to give you a better understanding of the different types of titanium and their typical uses.
Titanium is classified into two types—commercially pure (CP) titanium and titanium alloy. There are four grades of commercially pure titanium and several ways of classifying the dozens of titanium alloys. We’ll use a relatively simple classification that differentiates primarily according to material strength.
Commercially Pure (CP) Titanium
Commercially pure titanium contains more than 99% titanium with various amounts of carbon, hydrogen, iron, and oxygen to enhance strength. The greater the amount of oxygen, the greater the strength. The chart below indicates the maximum amount (percentage) of the element that can be added to titanium for each grade.
| Commercially Pure Titanium: Elements and Strength | |||||||
| GRADE | Carbon | Hydrogen | Iron | Nitrogen | Oxygen | Titanium | Tensile Strength (KSI) |
| 1 | 0.08 | 0.015 | 0.2 | 0.03 | 0.18 | Balance | 35 |
| 2 | 0.08 | 0.015 | 0.3 | 0.03 | 0.25 | Balance | 50 |
| 3 | 0.08 | 0.015 | 0.5 | 0.05 | 0.35 | Balance | 65 |
| 4 | 0.08 | 0.015 | — | 0.05 | 0.4 | Balance | 80 |
Because titanium has excellent corrosion resistance and is biocompatible, it’s often used in jewelry, eyeglass frames, implanted medical devices, and orthopedic and dental implants.
Alloys That Are Similar to Commercially Pure Titanium
Titanium alloys offer the same strength and corrosion resistance as pure titanium. Titanium acquires greater strength and workability when combined with varying traces of aluminum, chromium, cobalt, copper, iron, manganese, molybdenum, nickel, niobium, tantalum, vanadium, and zirconium. With these enhanced characteristics, titanium alloys have many more industrial applications compared to pure titanium. Three types of titanium alloys—grades 7, 11, and 12—are similar to commercially pure titanium.
- Grade 7 is similar to grade 2 commercially pure titanium and provides medium strength and ductility, as well as excellent weldability. It includes as much as 0.2% palladium, making it the most corrosion-resistant titanium alloy and ideal for piping, fittings, valves, condensers, and heat exchangers.
- Grade 11 is similar to grade 1 commercially pure titanium and offers optimum ductility, cold formability, and weldability. It includes as much as 0.25% palladium to enhance crevice corrosion resistance, making it useful for chemical processing, desalination, and marine applications.
- Grade 12 provides excellent high-temperature strength and weldability, as well as crevice corrosion resistance and acid resistance. It contains 0.6-0.9% nickel and 0.2-0.4% molybdenum.
Different Types of Titanium Alloys
There are several ways to classify the different types of titanium alloys—by strength, corrosion resistance, and high-temperature service. Here we’ll use titanium phases to compare the different types of titanium alloys and how they vary in their strength, weldability, and heat-treatability.
Titanium is an allotropic element, meaning it can exist in two or more different structural forms. Titanium has two dominant allotropic phases—alpha and beta (α+β)—that determine the different properties among titanium alloys. The alpha phase is a close-packed hexagonal structure, and the beta phase is a body-centered cubic structure.
Aluminum, oxygen, nitrogen, and carbon added to titanium induce the alpha phase. Vanadium, molybdenum, iron, chromium, and manganese added to titanium induce the beta phase. Alpha and beta alloys include combinations of elements used to induce the alpha and beta phases. The table below compares some of the key characteristics that would help guide the selection of the different types of titanium for fabricating a component or structure.
| Alpha Alloys | Alpha-Beta Alloys | Beta Alloys | |
| Heat-Treatable | no | yes | yes |
| Weldability | very good | most are weldable | generally weldable |
| Strength | low to medium | medium to high | highest |
| High-Temperature Creep Resistance | optimum | not as good as alpha | limited to intermediate temperatures |
The various amounts of elements that can be combined with pure titanium result in an overwhelming number of different types of titanium to choose from. Ti-6Al-4V is an alpha-beta titanium alloy and one of the most commonly used titanium alloys. Its primary alloying elements are aluminum and vanadium, giving the alloys low density and excellent corrosion resistance.
Where To Purchase Different Types of Titanium
The process to convert raw minerals into usable types of titanium is complex and costly. As a result, new titanium sourced directly from US mills is expensive compared to other common metals used in manufacturing. Industrial Metal Service offers an alternative to high titanium prices. Our inventory includes verified titanium remnants, commercially pure and alloyed, discounted well below the prices of new titanium.
