• Hafnium Diboride / Hafnium Boride Synonyms:

Hafnium boride, Hafnium diboride, Hafnium boride (HfB2), EINECS 234-500-7, CID6336857, 12007-23-7,  CAS #12007-23-7, powder, target, ceramic,  

• Hafnium Diboride / Hafnium Boride Designations:

Chemical Formula: HfB₂

• Hafnium Diboride / Hafnium Boride General Description:

a) Hafnium diboride is an ultra-high temperature ceramic composed of Hafnium and Boron.

b) It is an unusual ceramic, having relatively high thermal and electrical conductivities.

c) It is a grey, metallic looking material. Hafnium diboride has a hexagonal crystal structure, a molar mass of 200.11 grams per mole, and a density of 10.5 grams per cubic centimeter.

d) It has a melting temperature of about 3250 degrees Celsius.

e) The oxidation resistance of hafnium diboride is dependent on the temperature and pressure. At a temperature 1500°C and 1 atm of pressure, a protective oxide scale of hafnia forms. When temperatures rise above 1600°C and pressures drop below 1 atm, the oxidation resistance of HfB₂ is dramatically reduced. Under these conditions the boiling temperature of B₂O₃ (one of the oxidation products of HfB₂) is exceeded and the protective oxide layer.

• Hafnium Diboride / Hafnium Boride Typical Chemical Purities Available: #

a) ~Hf= 89.195 and B= 10.804

b) Purities Usually Available 99% to 99.99%

• Hafnium Diboride / Hafnium Boride Typical Granulations Available:

a) -140 + 325 mesh powder

b) Minus 325 mesh powder (APS= 10 microns or less)

c) Sputtering targets

• Hafnium Diboride / Hafnium Boride Typical Physical Constants:

• Hafnium Diboride / Hafnium Boride Typical Applications:

a) The material has potential for use in hypervelocity reentry vehicles such as ICBM heat shields or aerodynamic leading-edges, due to its strength and thermal properties. Unlike polymer and composite material, HfB2 can be formed into aerodynamic shapes that will not ablate during reentry.
 
b) Hafnium diboride is also investigated as a possible new material for nuclear reactor control rods.

c) It is also being investigated as a microchip diffusion barrier. If synthesized correctly, the barrier can be less than 7 nm thick.

• Hafnium Diboride / Hafnium Boride Packaging Options:

Steel drums

• Hafnium Diboride / Hafnium Boride TSCA (SARA Title III) Status:

Listed. For further information please call the U.S. Environmental Protection Agency at +1.202.554.1404

• Hafnium Diboride / Hafnium Boride Transportation:

Not classified as a hazardous material by the DOT.

• Hafnium Diboride / Hafnium Boride Chemical Abstract Service Number:

CAS# 12007-23-7