Dec 20 2012
Topics Covered
IntroductionPhysical PropertiesMechanical PropertiesThermal PropertiesApplications
Introduction
Hafnium is a ductile, lustrous silver metal which can easily resist corrosion due to the presence of a tough, impenetrable oxide film on its surface. The metal has very high melting point, and remains unaffected by acids and alkalis. The size of hafnium is same as that of zirconium. Alvite and hafnon are the two known ores of hafnium.
The following datasheet will discuss in detail about hafnium.
Physical Properties
The physical properties of hafnium are outlined in the following table.
| Properties |
Metric |
Imperial |
| Density |
13.31 g/cm³ |
0.4809 lb/in³ |
| Melting point |
2207-2247°C |
4005-4077°F |
Mechanical Properties
The mechanical properties of hafnium are outlined in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
485 MPa |
70300 psi |
| Yield strength (@0.02%, 315°C, longitudinal) |
125 MPa |
18100 psi |
| Elongation at break |
25% |
25% |
Thermal Properties
The thermal properties of hafnium are outlined in the following table.
| Properties |
Metric |
Imperial |
| Thermal expansion coefficient (@20°C/68°F) |
5.90 µm/m°C |
3.28 µin/in°F |
| Thermal conductivity |
22 W/mK |
153 BTU in/hr.ft².°F |
Applications
The following are the major applications of hafnium:
- Nuclear systems - control rods
- Super alloys
- Nuclear submarines
- High-temperature alloys and ceramics