What is Titanium?
Titanium is an exotic metal with a unique combination of mechanical, chemical and physical properties. Titanium has a relatively high price tag and requires special tools to fabricate the metal. This article provides some basics about Titanium, highlights its advantages over other metals and discusses common applications.
Titanium is element number 22 on the periodic table. It is a silvery metal that occurs naturally on Earth. Titanium is the 9th most common element on Earth. It is usually extracted from various minerals in the Earth's crust, such as ilmenite, sphene and rutile. However, it was not discovered by science until the late 18th century. Moreover, it was not used for industrial purposes until the 20th century.
22
Ti
47.867
What is the composition of Titanium?
Since Titanium is an element of the periodic table and not an alloy per se, it is possible to find virtually 100% pure Titanium.
However, it is often alloyed with other elements to further improve its physical and chemical properties. These different alloys are called 'grades'. There are about 50 grades of Titanium for sale, with some grades being much more popular than others. Grades 1, 2, 3 and 4 are all virtually pure titanium. Grade 5, one of the most widely used Titanium grades, contains significant amounts of aluminum and vanadium (each >3%).
Two examples of the most corrosion-resistant titanium grades are Grade 7 and Grade 11. They are 'almost pure' Titanium, with additions of palladium (<0.5%) that give them their excellent corrosion resistance.
There are many grades of titanium; these are just some of the most popular.
What are the properties of Titanium?
Titanium is best known for two properties..
- Corrosion resistance
- Strength-to-density ratio
Titanium has excellent corrosion resistance because oxygen molecules combine with Titanium to form Titanium oxides. This titanium oxide layer is passive and quite persistent, meaning it does not flake off like rust on steel and resists chemical attack from substances such as chlorine compounds.
Titanium also has a high strength-to-weight and strength-to-density ratio, meaning it is quite strong for how light it is. Some titanium grades, such as grade 5, have a significantly higher tensile strength than mild steel at just over half the density.
What is Titanium used for?
One of the most common applications for Titanium is in the aerospace industry. Its high strength and relatively low density make it a desirable metal for use in aircraft and missiles because of its fuel efficiency.
The maritime industry is another area that often relies on Titanium for its applications. This is because of its corrosion resistance, especially in saltwater environments where corrosion from chlorine is a problem.
Its excellent chemical resistance is also why it is used in chemical plants.
Many medical devices also use Titanium because of its strength and corrosion resistance.
Although not as popular as gold or silver, Titanium is sometimes used in various types of jewelry.
Titanium Grade 1-4 is pure Titanium, the other grades are alloys. Pure Titanium is used due to its high corrosion resistance, the alloys because of the extremely high strength to weight ratio.
- Grade 1. Pure Titanium, relatively low strength and high ductility.
- Grade 2. The pure titanium most used. The best combination of strength, ductility and weldability.
- Grade 3. High strength Titanium, used for Matrix-plates in shell and tube heat exchangers.
- Grade 4. Is commonly used in Aerospace, Industrial and Medical applications where high strength is needed.
- Grade 5. The most manufactured titanium alloy. Exceedingly high strength. High heat resistance.
- Grade 7. Superior corrosion resistance in reducing and oxidizing environments.
- Grade 9. Very high strength and corrosion resistance.
- Grade 12. Better heat resistance than pure Titanium. Applications as for Grade 7 and Grade 11.
- Grade 23. Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for surgical implant Applications.
CHEMICAL AND MECHANICAL PROPERTIES
| CHEM. COMP. | ASTM Grade | ||||||
| 1 | 2 | 5 | 7 | 9 | 12 | 23 | |
| Nitrogen | 0.03 | 0.03 | 0.05 | 0.03 | 0.02 | 0.03 | 0.03 |
| Carbon | 0.1 | 0.1 | 0.1 | 0.1 | 0.05 | 0.08 | 0.08 |
| Hydrogen | 0.0 15 |
0.0 15 |
0.0 125 |
0.0 15 |
0.0 13 |
0.0 15 |
0.0 125 |
| Iron | 0.2 | 0.3 | 0.4 | 0.3 | 0.25 | 0.3 | 0.25 |
| Oxygen | 0.18 | 0.25 | 0.20 | 0.25 | 0.12 | 0.25 | 0.13 |
| Palladium | 0.12-0.25 | ||||||
| Aluminum | 5.5-6.75 | 2.5-3.5 | 5.5-6.5 | ||||
| Molyb denum |
0.2-0.4 | ||||||
| Vanadium | 3.5-4.5 | 2.0-3.0 | 3.5-4.5 | ||||
| Nickel | 0.6-0.9 | ||||||
| MECH. PROP. | ASTM Grade | ||||||
| 1 | 2 | 5 | 7 | 9 | 12 | 23 | |
| Tensile strength, min (Mpa) | 240 | 345 | 895 | 345 | 620 | 483 | 828 |
| Yield strength, 0.2% Offset, min (Mpa) | 170 | 275 | 825 | 275 | 483 | 345 | 759 |
| Elongation (in 4D, min. %) | 24 | 20 | 10 | 20 | 15 | 18 | 10 |
| Reduction of Area, min. % | 30 | 30 | 25 | 30 | 25 | 25 | 15 |
| Hardness * Inter polated |
Rb 70 |
Rb 80 |
Rc 36 |
Rb 80 |
Rc 28 |
Rc 17* |
|
Image.. www.neonickel.com
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