Rhenium has one of the highest melting points only exceeded by tungsten & carbon. This metal is used in nickel-based superalloys which are used in high-temperature applications. It is the key component in the rheniforming process for producing gasoline and of filaments in mass spectrometers, ion gauges, and lamps in photoflash photography. 

Technical Informaiton

Crystal Structure: Hexagonal close-packed (hcp)

Melting Point: 3459 K ​ (3186 °C, ​5767 °F)

Boiling Point: 5903 K ​(5630 °C, ​10,170 °F)

Heat of Fusion: 60.43 kJ/mol