What is "alacrite"

Alacrite (also known as L-605, Cobalt L-605, Haynes 25, and occasionally F90) is a family of cobalt-based alloys. The alloy exhibits useful mechanical properties and is oxidation- and sulfidation-resistant.

One member of the family, XSH Alacrite, is described as "a non-magnetic, stainless super-alloy whose high surface hardness enables one to achieve a mirror quality polish." Originally developed for manufacturing aircraft components, L-605 has also been used in aerospace components and turbine engines as well as drug-eluting and other kinds of stents due to its biocompatibility. The Institut National de Métrologie in France has also used the material as a kilogram mass standard.