Titanium is not as abundant as iron or aluminum and it is not considered a precious metal, unlike gold and silver. However, because of its unique properties, it has become one of the most sought-after chemical elements. The advantages of this metal have brought forth a range of applications across different industries and sectors. Nonetheless, despite its superior characteristics, it also has some notable disadvantages.
Understanding the Advantages and Disadvantages of Titanium
English clergyman and mineralogist William Gregor discovered titanium in 1791 while on his longstanding pursuit of analyzing the chemistry of various minerals. He identified the then-unknown chemical element from a sample of black sands taken from Manaccan Valley in Cornwall and named it menaccanite. Furthermore, later that same year, German chemist Martin Heinrich Klaproth discovered and identified the same chemical element from the mineral rutile. He named what he thought was an unidentified metal “titanium” after the Titans of the Greek Mythology. Subsequent clarifications credited Gregor as the original discoverer.
Pros of Titanium: Properties and Key Applications
The use of titanium outside the lab was limited due to the complex and expensive processes involved in its extraction. Take note that it is found in nature as an oxide. Luxembourgish metallurgist William Justin Kroll introduced a more efficient process in 1932 that involved reducing titanium tetrachloride with calcium. He refined this process using magnesium and then sodium. The Kroll process enabled the commercial production of this chemical element. The Soviet Union pioneered the use of this metal in various military hardware applications during the 1950s and 1960s while the United States considered it a strategic material throughout the Cold War. Nevertheless, due to its properties, its industrial and commercial applications expanded. The following are the specific advantages of titanium:
1. Strong and Lightweight
One of the most important properties of titanium is that it is exceptionally strong for its weight. It has the highest strength-to-density ratio among all metallic elements. Pure grade forms have an ultimate tensile strength of about 434 MPa or 63000 psi. This is similar to the strength of common and low-grade steel. It is still about 60 percent denser than aluminum but is more than 200 percent stronger. This makes titanium ideal for aerospace, automobile, and medical implant applications where both strength and lightness are essential
2. Corrosion Resistance
This chemical element forms a passive, stable, and adherent oxide layer on its surface when exposed to oxygen. This layer acts as a barrier that limits the diffusion of corrosive agents such as water, acids, and alkalis. Furthermore, when damaged or scratched, the oxide layer is reformed upon exposure to oxygen. This property makes titanium suitable for applications where corrosion resistance is important. These include marine environments, offshore industries, chemical processing, aerospace, and medical implants.
3. High Heat Tolerance
Another advantage of titanium is that it retains its strength at high temperatures. It has a melting point of 1941 Kelvin and a boiling point of 3560 Kelvin. It also has low thermal expansion and is resistant to thermal cycling and thermal stress. This means that it expands and contracts less with temperature changes. This makes it ideal for applications in aerospace, engines, and industrial equipment that operate in extreme heat. The high melting point of this chemical element also makes it useful in the production of high-temperature materials.
4. Non-Toxic and Biocompatible
Titanium is non-toxic. It is also stable and does not degrade. The corrosion-resistant and lightweight properties of this chemical element also make it biocompatible. It also has a unique property called osseointegration that enables it to bond with bone tissue over time. In addition, because it is non-magnetic, it is compatible with diagnostic imaging techniques such as magnetic resonance imaging. These properties have made it applicable in bone and dental implants, bone screws, prosthetics, and surgical instruments.
5. Attractive Appearance
It might not be regarded as a precious metal unlike gold and platinum but it has an aesthetic appeal due to its metallic silver-grey color. It is ideal for making jewelry and other fashion accessories such as watches. Titanium is also used in some high-end consumer electronic devices and architectural designs due to its strength, light weight, and attractive appearance. The resistance to corrosion and tolerance to high temperatures also gives it a longer lifespan which reduces maintenance costs and makes it a more sustainable material.
Cons of Titanium: Notable Issues and Limitations
The range of applications of titanium suggests its industrial and commercial importance while also demonstrating its advantageous properties over other metals. Remember that it has a superior strength-to-density ratio than all other metals. Its resistance to corrosion makes it ideal for high-performance applications. However, despite its advantages, it is important to reiterate the fact that it is not as abundant as iron and aluminum. There are also various alternatives such as stainless steel and cobalt. This presents notable limitations of its applications. Some of its properties are also a drawback. The process of extracting this chemical element from minerals or compounds is still more expensive compared to more common or abundant metals. The following are the specific disadvantages of titanium:
1. High Production Costs
Titanium is the 9th-most abundant element and the 7th-most abundant metal on Earth. It accounts for 0.63 percent of the total mass of the crust. However, because it does not exist as a standalone chemical element, obtaining it requires extraction. The Kroll process remains the most efficient extraction process but it remains a complex and energy-intensive process. The cost of extraction is more expensive compared to iron and other more abundant metals. High production cost is a key disadvantage of titanium that limits its applications.
2. Complex Alloying
It is also important to note that a lot of its applications require alloying or mixing the chemical element with other chemical elements aluminum, vanadium, or nickel. Alloying can enhance further its strength, improve its high-temperature performance, reduce material use, enable weldability, improve its fatigue resistance, or add color and aesthetics. Creating these alloys is a complex process that requires specialized manufacturing and contamination prevention. The cost of alloying elements can add to the overall production cost.
3. Difficulty in Machining
Another disadvantage of titanium is that it is hard to cast or difficult to machine, unlike iron and aluminum. Remember that this chemical element has the highest strength-to-density ratio among all metallic elements. It also has a high melting point due to its high heat resistance. These apparent advantageous properties translate to problems in casting or machining this metal to shape it according to the desired form. It requires specialized tools and techniques. It is also prone to contamination during the production process.
4. Low Thermal Conductivity
The low thermal conductivity of this metal gives it a high resistance to the ill effects of high temperatures. It can retain its strength and is less vulnerable to thermal stress despite repeated exposure to heat. However, because it does not conduct heat very well, it is difficult to weld with other metals with different expansion and contraction rates. It is also prone to heat accumulation and overhearing when exposed to high temperatures for an extended period. This makes it unsuitable for some consumer electronics applications.
5. Recycling Challenges
Longevity due to durability is another advantage of titanium. This advantage also translates to another disadvantage. Titanium can be hard to recover for recycling or upcycling purposes from discarded products and other post-consumption materials. This comes from the fact that it has a high melting point that can make material separation difficult. The strength of this metal or its allows can also present a challenge in reforming and recombining. Contamination prevention adds another layer to its overall complex recycling process.
FURTHER READINGS AND REFERENCES
- Boyer, R. R. 2010. “Attributes, Characteristics, and Applications of Titanium and Its Alloys. JOM: The Journal of the Minerals, Metals, and Materials Society. 62(5): 21-24. DOI: 1007/s11837-010-0071-1
- Krebs, R. E. 2006. The History and Use of Our Earth’s Chemical Elements: A Reference Guide. 2nd ed. Greenwood Press. ISBN: 978-0-313-33438-2.
- Pushp, P., Dasharath, S. M., and Arati, C. 2022. “Classification and Applications of Titanium and Its Alloys. Materials Today: Proceedings. 54: 537-542. DOI: 1016/j.matpr.2022.01.008