Titanium Alloy – Reinventing The Wheel

Consumers are intimately familiar with certain metals. Silver and gold jewellery. Steel automobiles. Aluminium cans. On the other hand, if you ask them about titanium alloy, they’d likely be unable to describe how it affects their lives.

Titanium, the fourth most abundant metal on earth, is about as strong as steel, and twice as strong as aluminium. It’s forty-five percent lighter than steel, yet only sixty percent heavier than aluminium. It is capable of withstanding high temperatures, is non-reactive to the human body, and resists corrosion.

If it weren’t for prohibitive costs related to processing this abundant element, I am sure it would be completely recognisable to everyone. Titanium has proved resistant to mass production. Magnetic black sand, discovered in 1791, introduced titanium to the world. The first pure sample of the metal took place in 1910. The first commercially suitable process for isolating titanium from other minerals it bonds with was not developed until 1937. The Kroll method, as it was known, remains the most common method of extracting pure titanium at the dawn of the 21st century. The first mining operation for titanium started a decade after Kroll’s method was patented.

The difficulty with extracting pure titanium has ironically resulted in it being a space-age material used for high-tech applications. After the ore is mined, it undergoes a multi-step process to remove impurities. Once pure titanium is isolated, it is alloyed in huge furnaces. Aluminium and vanadium are often used, but other elements may be introduced too, depending on its anticipated use. (The American Society for Testing and Metals – ASTM – has forty distinct grade classifications of titanium alloys.)

With the exception of a brief period when the United States military was the primary developer of titanium alloy applications, approximately eighty percent of all titanium use takes place within the aerospace industry, where strong, lightweight, heat resistant material is critical in successfully sending a plane into the sky or shooting a satellite into orbit. The remaining twenty percent of titanium production has occurred in the medical field for biological implants due to its compatibility with the human body, in marine applications such as boat propellers, where exposure to seawater would quickly cause other metals to corrode, and a tiny fraction used in consumer products (jewellery, paper whitening, and white paint pigment, for instance.)

These percentages may see major shifts soon. Until recently, furnaces used to process titanium have been too small to provide sufficient quantities of titanium and titanium dioxide to allow it to be used in many applications for which it is well suited. The Kroll method produces toxic pollutants that are expensive to treat.

Recent developments are expanding titanium alloys’ potential uses. Titanium hydride does not have the heat resistance necessary for aerospace applications but retains other favourable titanium traits for about one-eighth of the cost of producing titanium dioxide by the Kroll method. Non-melt titanium condensation methods are expected to enable large scale use for military armour and automobiles. Today, titanium and its alloys are used in sunscreens and high-end sporting equipment. As supply stabilises and the cost of acquiring titanium alloy continues to decrease, it is likely to be a component of choice for many more consumer applications.