Jul 15 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Beryllium is a chemical element with atomic number 4, represented by the chemical symbol ‘Be’. It is a toxic, bivalent element having a steel gray appearance. It is a lightweight metal having very high melting point and good thermal conductivity. It is non-magnetic by nature and exhibits good resistance to corrosion due to exposure to air and contact with nitric acid. Beryllium belongs to the alkaline earth metal category, s-block and period 2 of the periodic table.
Beryllium content on earth’s crust is 2.6 ppm. It is one of the most toxic elements, hence causes damage to human lungs and other organisms. It is found in as many as 30 different minerals.
Chemical Properties
The chemical properties of beryllium are provided in the table below:
Chemical Data |
CAS number |
7440-41-7 |
Thermal neutron cross section |
0.0090 barns/atom |
Electrode potential |
-1.70 V |
Ionic radius |
0.350 Å |
Electro negativity |
1.57 |
X-ray absorption edge |
110.68 Å |
Electrochemical equivalent |
0.168 g/A/h |
Physical Properties
The following table discusses the physical properties of beryllium.
Properties |
Metric |
Imperial |
Density |
1.844 g/cm3 |
0.066 lb/in3 |
Melting point |
1273-1293 °C |
2323-2341 °F |
Boiling point |
2970 °C |
5378°F |
Mechanical Properties
The mechanical properties of beryllium are tabulated below.
Properties |
Metric |
Imperial |
Tensile strength |
370 MPa |
53700 psi |
Modulus of elasticity |
303 GPa |
43900 ksi |
Shear modulus |
135 GPa |
19600 ksi |
Hardness, Rockwell B |
75-85 |
75-85 |
Elongation at break |
3% |
3% |
Thermal Properties
The thermal properties of beryllium are tabulated below.
Properties |
Metric |
Imperial |
Thermal expansion co-efficient (@25°C/77°F) |
11.5 µm/m°C |
6.39µin/in°F |
Thermal conductivity |
216 W/mK |
1500 BTU in/hr.ft².°F |
Applications
The following are the application areas of beryllium:
-
Alloying agent in production of beryllium-copper
-
X-ray detection diagnostics
-
Manufacture of computer peripherals
-
Nuclear reactors as neutron moderators and reflectors
-
Satellite structures
-
IR target acquisition
-
Heat sink constraining cores
Beryllium alloys are used in defense and aerospace industries.