By: 1 October 2008

What Is Oxidized Zirconium?

Oxidized zirconium (Oxinium™ – Smith & Nephew) is a product of new hybrid technology which seeks to combine the properties of metals and ceramics into a single substance. Specifically, it is an oxidized zirconium surface layer on underlying zirconium metal. The underlying base metal is a zirconium-niobium alloy and the surface layer is oxidized zirconium (aka zirconia) which is one of the common ceramic bearing surfaces used in orthopaedics. However what is unusual about this hybrid technology is that unlike previous attempts to combine material properties such as hydroxyapatite on stainless steel femoral stems, this oxidized zirconium is not an applied coating to the underlying zirconium metal but rather a change is the structure of the zirconium itself at its surface.

A typical component is first forged or machined from a wrought alloy of zirconium (97.5%) and niobium (2.5%). The component is then heated in air at about 500