The Physical Properties of Titanium
Titanium’s value in everything from aerospace designs to surgical equipment is directly related to its physical characteristics. While titanium is one of the most abundant metals in the earth’s crust, and as the technology for extraction and processing continues to get better, it will likely be implemented in many more industrial, medical, and other products.
Titanium is lightweight, strong, and extremely resistant to corrosion. It has a shiny, dark gray/silver appearance and is non-toxic in the human body (which is why it is used in surgical tools). By understanding more about its physical properties, though, it’s easier to see why this metal is so beneficial.
Tensile Strength – Titanium and its alloys have a tensile strength that runs from 20,000 psi to over 200,000 psi. Commercial grade titanium is usually around 63,000 psi. The softest grade of commercially pure titanium is around 240 MPa, while high-strength alloys can go as high as 1,400 MPa. Grade 4 commercially pure could be up to 552 MPa.
Weight – Titanium is about 45% lighter than steel. While it is 60% heavier than aluminum, it is twice as strong.
Density – At 4.54 grams per cubic centimeter, titanium is about 56% as dense as steel.
Hardness – When oxygen is absorbed into the surface of titanium when the metal is hardened, it can greatly increase the hardness of the surface layer. (This is often an indicator of the tensile strength.)
Fatigue Strength – Titanium alloys have high-cycle fatigue strength. This will vary depending on the surface finish, so care must naturally be applied to avoid stress concentrators.
Melting Point – This metal will melt at 3,034°F (1,668°C) which is about 400°F above steel, and around 2,000 above aluminum.
Thermal Expansion – The coefficient of thermal expansion (the amount it expands or lengthens when heat is applied) of titanium is relatively low.
Electrical Conductivity – Titanium is not a good conductor. It is similar to stainless steel in conductivity.
Magnetics – Commercially pure titanium and all the associated alloys are non-magnetic.
Alloys – Titanium can be alloyed with aluminum, molybdenum, iron, manganese, and many metals.