Cobalt-chrome turbines, and many others. The common Co-Cr alloy production requires the extraction of cobalt and chromium from cobalt oxide and chromium oxide ores. Both of the ores need to go through reduction process to obtain pure metals. Chromium usually goes through aluminothermic reduction technique, and pure cobalt can be achieved through many different ways depending on the characteristics of the specific ore. Pure metals are then fused together under vacuum either by electric arc or by induction melting. Due to the chemical reactivity of metals at high temperature, the process requires vacuum conditions or inert atmosphere to prevent oxygen uptake
Cobalt zinc oxide), and cobalt violet (cobalt phosphate) are used as artist's pigments because of their superior chromatic stability. Aureolin (cobalt yellow) is now largely replaced by more lightfast yellow pigments. Cobalt-60 (Co-60 or Co) is useful as a gamma-ray source because they can be produced in predictable quantity and high activity by bombarding cobalt with neutrons. It produces gamma rays with energies of 1.17 and 1.33 MeV. Cobalt is used in external beam radiotherapy, sterilization of medical supplies and medical waste, radiation treatment of foods for sterilization (cold pasteurization), industrial radiography (e.g. weld integrity radiographs), density measurements (e.g. concrete density