Hafnium metal is a kind of transition metal of silver gray metallic, which is in powder, rod, ingot, bar, target and piece. It exists accompany with zirconium normally. There are two crystal structures of hafnium, one is hexagonal close packing (α-type at less than 1300℃, the other is body-centered cubic (β-type). Hafnium is ductile metal, however it turn hard and brittle when impurities exist. It is stable in air and turn dark when igniting. Hafnium wire can ignite by match. Its property is close to zirconium. It is soluble in aqua regia and hydrofluoric acid, but doesn’t dissolve in water, dilute acid or alkali. Hafnium alloy (Ta4HfC5) is the material of highest melting point that is about 4215℃ at present.
|CAS No.:7440-58-6||EINECS No.: 231-166-4||Molecular Formula:Hf||Molecular Weight:178.49|
|Melting Point:2227℃||Boiling Point:4602℃||Density:13.3||UN 1326 4.1/PG 2|
Hafnium metal can be as cathode of X-ray tube. Hafnium alloys with tungsten or molybdenum can be as electrode of high voltage discharge tube. Hf-Ta alloy is raw material for chisel tool steel and resistance material.
Hafnium powder can be thruster of rocket. it is a kind of additive for hydraulic oil, which prevent the volatilization when high-risk operations. It has strong resistance to volatile. It works in industrial hydraulic oil and medical hydraulic oil.