Chemical and physical properties of titanium

Titanium is a strong and lightweight refractory metal. Titanium alloys are vital to the aerospace industry and are also used in medical, chemical and military hardware as well as sports equipment.

Aerospace applications account for 80% of titanium consumption, while 20% of the metal is used in armor, medical hardware and consumer products.

Titanium properties

When it comes to the properties of titanium, we cannot ignore its unique physical properties. Titanium is a lightweight metal with a density of 4.5 grams per cubic centimeter, giving it excellent strength. This balance of strength-to-weight ratio makes titanium a scaffold material in the aerospace field and promotes the development of modern aircraft.

Atomic symbol: Ti

Atomic number: 22

Element Category: Transition Metal

Density: 4.506/cm 3

Melting point: 3038°F (1670°C)

Boiling point: 5949°F (3287°C)

Mohs hardness: 6

feature

Titanium-containing alloys are known for their high strength, light weight, and excellent corrosion resistance. Although titanium is as strong as steel, it is about 40% lighter.

This, coupled with its resistance to cavitation (rapid pressure changes that cause shock waves that weaken or damage the metal over time) and erosion, makes it an essential structural metal for aerospace engineers.

Titanium is also highly resistant to corrosion by water and chemical media. This resistance is caused by the formation of a thin layer of titanium dioxide (TiO 2 ) on its surface, making these materials extremely difficult to penetrate.

Titanium has a lower modulus of elasticity. This means that titanium is very flexible and can return to its original shape after bending. Memory alloys (alloys that deform when cold but return to their original shape when heated) are important for many modern applications.

Titanium is non-magnetic and biocompatible (non-toxic, non-allergenic), which has led to its increasing use in the medical field.

history

To understand the industrial importance of titanium, we need to look back at its history. The discovery of titanium dates back to the 18th century, but its destructive form was not successfully isolated until the 20th century. In the past few decades, titanium has gradually come to prominence and become the mainstay of science and technology. With the rise of the aviation industry, titanium alloys have become an ideal choice for aircraft structures. Their lightweight and high-strength properties make aircraft not only more energy-efficient, but also safer.

The use of titanium, in any form, only really developed after World War II. In fact, titanium was not isolated as a metal until 1910 when American chemist Matthew Hunter produced titanium by reducing titanium tetrachloride (TiCl 4 ) with sodium; a method now known as the Hunter process.

However, commercial production was not possible until the 1930s when William Justin Kroll demonstrated that magnesium could also be used to reduce titanium from chloride. The Kroll process remains the most commonly used commercial production method today.

Titanium's first major use was in military aircraft after a cost-effective production method was developed. The Soviet Union and the United States began to use titanium alloys in military aircraft and submarines designed in the 1950s and 1960s. By the early 1960s, commercial aircraft manufacturers also began using titanium alloys.

Research by Swedish doctor Per-Ingvar Branemark dating back to the 1950s showed that titanium does not trigger a negative immune response in the human body, allowing the metal to integrate into our bodies. It's called osseointegration.

Production

Titanium is a widely used light metal whose production mainly relies on the chlorination method. In this process, titanium ore usually reacts with chlorine gas and coke to generate titanium chloride, which is then reduced to pure metallic titanium through high temperature. This unique and complex production process provides us with a strong, lightweight titanium material to lay the foundation for applications in a variety of fields.

Although titanium is the fourth most common metallic element in the earth's crust (after aluminum, iron and magnesium), the production of titanium metal is extremely sensitive to pollution, especially oxygen, which is why its development is relatively new and costly.

The main ores used in primary titanium production are ilmenite and rutile, accounting for approximately 90% and 10% of production respectively.

The production of ilmenite concentrate in 2015 was close to 10 million tons, although only a small proportion (about 5%) of the ilmenite concentrate produced each year is ultimately converted into titanium metal. Instead, most is used to produce titanium dioxide (TiO 2 ), a whitening pigment used in paints, food, pharmaceuticals, and cosmetics.

In the first step of the Kroll process, titanium ore is crushed and heated with coking coal in a chlorine atmosphere to produce titanium tetrachloride (TiCl 4 ). The chloride is then captured and passed through a condenser, producing titanium chloride liquid with a purity of up to 99%.

The titanium tetrachloride is then fed directly into the vessel containing molten magnesium. To avoid oxygen contamination, make it inert by adding argon.

The subsequent distillation process can take several days, during which the vessel is heated to 1832°F (1000°C). Magnesium reacts with titanium chloride, stripping off the chloride and producing elemental titanium and magnesium chloride.

The resulting fibrous titanium is called sponge titanium. To produce titanium alloys and high-purity titanium ingots, electron beam, plasma arc or vacuum arc melting can be used to melt titanium sponge with various alloying elements.

use

The application of titanium metal in the field of sporting goods is mainly reflected in high-end bicycles, golf clubs, tennis rackets and other equipment. The lightweight properties of titanium metal make sports equipment more flexible and comfortable, improving the competitive level of athletes.

Titanium metal is widely used in aerospace, automotive industry, medical equipment, chemical industry, electronics and sporting goods and other fields. With the continuous development and progress of science and technology and the improvement of technology, the application fields of titanium metal will continue to expand. The excellent properties and versatility of titanium metal make it an indispensable part of modern engineering materials.

 

〔Quote〕Bell, Terence. "Properties and Properties of Titanium." ThoughtCo, 4 April 2023, thoughtco.com/metal-profile-titanium-2340158.