Jul 29 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Rhenium is a silvery-white metal, with one of the highest melting points of all metals. With an average concentration of 1 ppb, rhenium is one of the rarest elements in the Earth’s crust.
It is usually available in powdered form, but it can be consolidated by pressing and sintering in the presence of vacuum or hydrogen. At room temperature and atmospheric pressure, the element is resistant to hydrochloric acid, alkalis, and aqua regia.
Chemical Properties
The chemical properties of rhenium are provided in the table below.
|
Chemical Data |
|
CAS number |
7439-96-5 |
|
Thermal neutron cross section |
12.6 barns/atom |
|
Electrode potential |
-1.05 V |
|
Ionic radius |
0.460 Å |
|
Electronegativity |
1.55 |
|
X-ray absorption edge |
1.896 Å |
|
Electrochemical equivalent |
0.684 g/A/h |
Physical Properties
The following table discusses the physical properties of rhenium.
|
Properties |
Metric |
Imperial |
|
Density |
21.03 g/cm3 |
0.7598 lb/in3 |
|
Melting point |
3180°C |
5760°F |
|
Boiling point |
5596°C |
10105°F |
Mechanical Properties
The mechanical properties of rhenium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1070 MPa |
155000 psi |
|
Yield strength |
290 MPa |
42100 psi |
|
Poisson’s ratio |
0.296 |
0.296 |
|
Modulus of elasticity |
469 GPa |
68000 ksi |
|
Shear modulus |
176 GPa |
25500 ksi |
|
Elongation at break |
15-25% |
15-25% |
|
Hardness, Brinell |
165 |
165 |
|
Hardness, Vickers |
170 |
170 |
|
Hardness, Rockwell A |
52 |
52 |
|
Hardness, Rockwell B |
85 |
85 |
Thermal Properties
The thermal properties of rhenium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@500°C/932°F) |
6.12 µm/m°C |
3.40 µin/in°F |
|
Thermal conductivity |
39.6 W/mK |
275 BTU in/hr.ft².°F |
Applications
Rhenium is included in high-temperature superalloys used for manufacturing jet engine parts. Platinum-rhenium catalysts that are chiefly used in lead-free, high-octane gasoline are another major application of rhenium.
Rhenium is added to nickel-based super alloys to improve creep strength of the alloys. Rhenium filaments exhibit a higher stability, and hence they can be used in photoflash lamps, ion gauges and mass spectrometers.
Rhenium radioactive isotopes are used for treating liver and pancreatic cancer where it is delivered through a bacterial host.