Rhenium enhances the physical properties of Tungsten. Tungsten Rhenium alloys has higher plasticity at low temperatures, which is easier to manufacture and shape, and has improved stability at high temperatures. This change increases with the Rhenium content, and Tungsten Rhenium alloys can contain up to 27% Rhenium, which is the solubility limit of Rhenium in Tungsten. X - ray sources are one of the applications of Tungsten Rhenium alloys. Both Tungsten and Rhenium have high melting points and atomic weights, which helps them resist constant electron bombardment. This alloys is also used as a thermocouple and can measure temperatures up to 2200°C.