Titanium applications: aerospace, medicine, chemistry and construction

Titanium is a strong and relatively light metal with high corrosion resistance and a good strength-to-weight ratio. As a structural metal, it is not used as a universal replacement for steel. It is chosen where low weight, resistance to aggressive environments, durability or biocompatibility justify the higher cost. At the same time, a large share of titanium consumption is not metallic titanium, but titanium dioxide, a white pigment used in paints, plastics, paper and other products.

Properties and characteristics of titanium

The main practical properties of titanium include:

• high corrosion resistance, including in seawater and many chloride environments;
• a good strength-to-weight ratio;
• a relatively high melting point;
• stable performance across a wide temperature range;
• formation of a protective oxide film on the surface;
• good biocompatibility of selected grades and alloys.

Titanium also has limitations. It is more expensive than common structural steels, harder to machine and weld, and is not economical for many low-cost mass products. For that reason, titanium is normally selected only when its properties clearly offset its cost.

Titanium grades and alloys

Industry uses commercially pure titanium and titanium alloys. Commercially pure grades are selected where ductility and corrosion resistance are especially important. Alloys with aluminium, vanadium, molybdenum, nickel and other elements are used to increase strength, heat resistance or performance under load.

The grade affects strength, ductility, weldability, corrosion resistance and the allowable operating temperature. A medical implant, heat exchanger, aerospace part, fastener or decorative element may therefore require different titanium grades and different surface quality.

Where titanium is used

Titanium and its alloys are used in several major areas:

• aerospace - airframe parts, fasteners, landing gear elements, engine components, hydraulic systems and other parts where strength, low weight and heat resistance matter;
• chemical and petrochemical equipment - heat exchangers, pipes, vessels, tanks, pump parts and fittings operating in corrosive media;
• energy and water treatment - condensers, heat exchangers, cooling systems, desalination equipment and parts in contact with salty or contaminated water;
• marine equipment - ship components, fasteners, pump parts, heat exchangers and parts exposed to seawater;
• medicine and dentistry - implants, plates, screws, dental structures, surgical tools and prosthetic components;
• food processing - tanks, filters, heat exchangers, pipes and equipment parts requiring corrosion resistance and hygiene;
• sport, consumer goods and design - bicycles, watches, eyeglass frames, jewellery, electronics housings, outdoor and sports equipment.

Titanium in construction

In construction, titanium is used less often than steel, aluminium or copper, but it can be valuable in demanding and decorative elements. It may be used for roofing and facade parts, cladding, decorative panels, fasteners, cornices, columns and exterior elements that need a long service life.

The main reasons for using titanium in construction are corrosion resistance, durability, relatively low weight and resistance to atmospheric exposure. Because of its price, it is selected selectively for buildings with high requirements for service life, appearance or operation in aggressive environments.

What to consider when selecting titanium

Titanium should not be selected by name alone. The grade, supply condition, product form, surface quality, welding conditions, operating temperature, contact environment and strength requirements are all important. Seawater, chemical equipment, medical devices and facade panels impose different demands, so final selection should be based on standards, the project and manufacturer recommendations.

Related materials

• Titanomagnetite ore specific weight