The world knows titanium as one the metallic elements and anyone who works in the field of materials specially metallic materials know how useful this element is. In reality, titanium is a chemical element and titanium periodic symbol is ti. Ti element has the atomic number 22 and is found in the earth crust only in oxide form.
Using different concentration, refining, and metal production techniques, this titanium oxide can be reduced to produce titanium metal which is a lustrous transition metal. Titanium color is silver in appearance and has lower density as compared to steel.
When compared to steel, titanium metal and titanium deep drawing have higher strength, higher corrosion resistance when exposed to sea water or chlorine. Its strength to density ratio is much higher as compared to steel.
The question of when was titanium discovered is quite interesting. Titanium in its oxide form was present in earth crust when earth was formed billions of years ago. However it came to be known to humans when William Gregor discovered some unknown oxides in 1791 while testing iron oxide in Cornwall Great Britain.
William Gregor, who discovered titanium (the ti element) named titanium after a Greek Titan Martin Heinrich Klaproth. The ti element occurs with ilmenite, principally rutile and a number of minerals and all these are widely available and distributed in earth crust.
Titanium is considered as one of the basic building blocks of life and its traces can be found in all living things found on earth. Ti element can be found in rocks, earth soil and water bodies. To extract titanium element from its basic mineral deposit a famous Kroll and Hunter process is used.
Just like titanium oxide, titanium dioxide is one of the most common titanium components that exist in the earth crust. This compound of titanium uses as a photocatalyst in production of white pigments.
Other titanium compounds include titanium trichloride and titanium tetrachloride. These compounds of titanium uses as catalysts for production of polypropylene and components of smoke screen respectively.
Titanium is usually alloyed with other metals like iron, vanadium, aluminum and molybdenum to make it useful for different industrial use.
Researchers from the United States of America developed a titanium alloy in 1954 called Ti-6Al-4V. It was developed for excellent heat resistance, high strength, high toughness, good plasticity, and excellent manufacturing properties like weldability and formability.
This alloy also has very high corrosion resistance and is biocompatible. This alloy of titanium was labeled as the first practical titanium alloy.
From about 10 years (1950-1960) the main focus and demand from the aerospace industry was to develop a titanium alloy that has very high temperature resistance for use in jet engines. At that time research was done to give titanium the temperature resistance of 400C which was then improved to about 650C in 1990.
During this time titanium alloys like A2(TiAl) and r(TiAl) were developed. This promotes titanium parts from the front end of the engine (low temperature region) to the back end of engine (high temperature region).
Similarly from 1970 to 1980, there was a lot of work done to increase the corrosion resistance of titanium alloys for marine and underwater vehicle use. At the same time a lot of work is done on structural titanium alloys and memory titanium alloys.
There are hundreds of titanium alloys with each having its own unique properties. Here we will discuss some general properties of titanium with some unique properties of its alloys.
Titanium is solid at room temperature and has a melting point of 1668C whereas its boiling point is 3287C. Density of titanium is about 4.506 gram per cubic centimeter which is far less than that of steel at 7.85 gram per centimeter cube.
Titanium with 99.2 % of titanium is considered pure and has a strength of about 434 MPa. This strength is equal to a low grade steel alloy. When compared to aluminum, the strength of titanium is twice as high and density about 60% more than that of aluminum.
Some alloys of titanium like Beta C titanium alloy have tensile strength of about 1400 MPa which is about three times that of the structural steel. Fatigue strength of titanium is much more than that of the structural steel.
Titanium is not as hard as some high quality heat treated grades of steel. Titanium is a non magnetic material and it is a very poor conductor of heat and electricity.
Titanium is one of the most difficult materials to manufacture with. Due to its extreme strength, temperature and wear resistance it is very difficult to process titanium and manufacture parts.
Machining of titanium alloys needs special modification in the machining process both in terms of cutting tools and machining setup. Due to its strength and wear strength higher than steel, most common cutting tools that perform well on steel will not work on titanium.
To machine titanium, special tools like carbide tips and diamond coated tips and special machining setup like heating of titanium to reduce its strength or using liquid nitrogen to reduce temperature related damage done on tool during machining are needed.
Similar cast of titanium alloy is near to impossible. With a melting point around 1,668°C, melting and pouring titanium into molds demand specialized equipment and processes.
Titanium's reactivity with oxygen, nitrogen, and hydrogen necessitates stringent control of the casting environment to prevent contamination and maintain desired mechanical properties. Moreover, the metal's brittleness at high temperatures increases the risk of cracking and other defects during casting.
Opposite to this, extrusion forming and sheet metal welding services of the titanium is extremely good. Although you still need to consider the high temperature resistance of titanium during welding, and its extreme strength during forming, still it's easier to process titanium through welding and forming as compared to subtractive machining and cast.
Titanium that was discovered in 1791 is now the backbone of several industries, especially aerospace. Due to its high strength, temperature and corrosion resistance, it can be used in numerous aerospace and marine applications. With all recent development in terms of both products and their manufacturing processes. The importance and use of titanium will increase in coming years.
