Hafnium
Hafnium, element symbol Hf, atomic number 72, atomic weight 178.49, belongs to group IVB of the periodic table. Hafnium is a lustrous silver-gray transition metal with a density of 13.31 g/cm³ (20 °C), a melting point of 2233 °C (2506 K, 4051 °F), and a boiling point of 4603 °C (4876 K, 8317 °F).
Applications of hafnium
1, hafnium metal has excellent welding properties, processing properties, high temperature corrosion resistance, and thus become an important material for the atomic energy industry.
2, hafnium's thermal neutron capture cross-section is large, is a more ideal neutron absorber, can be used as an atomic reactor control rods and protection devices.
3, hafnium can be used as a lot of inflatable system absorber. 
