Titanium: Light Weight but as Strong as Steel

by Rebekah Fuller, IQS Editor

Rebekah Fuller Author Pic

Named after the mythological giants, the Titans, titanium was discovered in the late 1500s. Unlike tungsten’s superior strength and high density, making it the metal of choice for many tough applications from drill bits and cutting tools to impenetrable tank armor, titanium combines great strength but at low density, making it as strong as steel but half the weight per volume, plus it is ductile, corrosion resistant and heat resistant. The military, automotive, jewelry and aerospace industries, among others, buy titanium products. Titanium tubing, pipes, wire, bars, plate, foil, rods and sheet are either distributed, used as parts, or further processed. Let’s see how this important metal was first utilized.

The titanium metal industry was established in the 1950s to serve the emerging aerospace industry. Titanium’s properties made it invaluable in the manufacture of airframe structural components and skin, aircraft hydraulic systems, engine components, rockets, missiles and spacecrafts. It is easy to see why a strong, resistant metal—30% stronger than steel but also nearly 50% lighter—would be prized in components that need to defy gravity in the sky and beyond. Titanium also has excellent strength retention to 1,000 degrees Fahrenheit; the military took notice for use in guided missiles and artillery too.

Titanium Carving

Photo courtesy of Titanium Processing Center.

Though titanium is rather expensive to extract and manufacture, many industries choose it even at a higher cost. Once processed into foil, sheet, wire, granules, sponge, powder, mesh and rod, it is relatively easy to fabricate and extremely useful, which is why so many industries keep coming back to it and continually research new possible uses. Titanium is a naturally and abundantly occurring element (the ninth most abundant on Earth—more than nickel, zinc, chromium, tin, lead, mercury and manganese combined!), but its ores are dispersed throughout the earth’s crust unlike other metals’ that are concentrated in large, easily mined bodies. Titanium is contained in deposits of ilmenite ore, a titanium-iron oxide mineral, and extracted most often using the Kroll Method, which involves reducing titanium tetrachloride with magnesium. This reduction yields a raw and highly porous “titanium sponge” material that can be pressed or melted into blocks, bars, castings and other forms for fabrication. As the widely recognized father of the modern titanium industry, Wilhelm Kroll developed this method of manufacturing titanium in the 1930s and ‘40s, and it is still used today.

Titanium Sponge

Ilmenite Ore.

Titanium Carving Equipment Titanium Carving Titanium Industrial Facility

Photos courtesy of Titanium Processing Center.

The price of titanium products did drop some with the dawning of the 1970s, and other practical applications emerged, such as in submarines, ship’s propellers, shafts, rigging and other parts that need to stand up to a highly corrosive salt water environment. Titanium’s highly corrosion resistant character comes out when exposed to the atmosphere. It forms a tight, tenacious oxide film resilient to salt water and many corrosive materials. Today’s increasing uses for titanium include medical applications, such as orthopedic and prosthesis devices and catheters, due to its light weight, strength and hypoallergenic properties, as titanium is nickel free. Many automotive parts—such as valve springs, rocker arms, connecting rods, exhaust systems, drive shafts and steering gears—utilize titanium, and racing sports take advantage of the metal to increase vehicular speed. Specialized applications include semiconductor and battery titanium wires, chemical and petroleum handling, agri-food titanium tubing, sporting goods equipment, jewelry and gem fabrication. Plus, titanium dioxide is a brilliant white pigment used in paints, toothpastes, paper, plastics and food coloring, like the little m’s on M&M’S® candies.

Titanium Processing Center

Photos courtesy of Titanium Processing Center.

There are 38 titanium grades as classified by the American Society for Testing and Materials (ASTM). The first 5 grades are unalloyed, and the rest are titanium alloys. Adding titanium to aluminum, manganese, iron, molybdenum and other metals means increased strength, withstanding higher temperatures and lightening the resultant alloy. Whether you want to be an astronaut or want a durable, attractive ring that is 100% hypoallergenic, you will encounter titanium in some shape or form.