Aug 13 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Indium is a chemical element with ‘In’ as its symbol. It belongs to group 13 and has the atomic number 49.
Indium is very soft with high plasticity, malleability and ductility. It has good corrosion resistance to water and alkalis. It generally occurs within iron, lead, zinc, and copper ores. It is stable in air but dissolves in acids. It burns with a violet flame when heated above its melting point.
Canada is the leading producer of indium.
Chemical Properties
The chemical properties of indium are provided in the table below.
|
Chemical Data |
|
CAS number |
7440-74-6 |
|
Thermal neutron cross section |
196 barns/atom |
|
Electrode potential |
-0.340 V |
|
Ionic radius |
0.810 Å |
|
Electronegativity |
1.78 |
|
X-ray absorption edge |
0.44397 Å |
|
Electrochemical equivalent |
1.4 g/A/h |
Physical Properties
The following table discusses the physical properties of indium.
|
Properties |
Metric |
Imperial |
|
Density |
6.916 g/cm3 |
0.2499 lb/in3 |
|
Melting point |
156°C |
313°F |
|
Boiling point |
2000°C |
3632°F |
Mechanical Properties
The mechanical properties of indium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
4.50 MPa |
653 psi |
|
Modulus of elasticity |
12.7 GPa |
1840 ksi |
|
Shear modulus |
4.40 GPa |
638 ksi |
|
Hardness, Brinell |
0.9 |
0.9 |
|
Hardness, Vickers |
≤ 10 |
≤ 10 |
Thermal Properties
The thermal properties of indium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-100°C/68-212°F) |
33 µm/m°C |
18.3 µin/in°F |
|
Thermal conductivity |
83.7 W/mK |
581 BTU in/hr.ft².°F |
Applications
The following are the application areas of indium:
-
Rectifiers
-
Solar cells
-
Thermistors
-
Semiconductors
-
Photoconductors
-
To dope germanium to make transistors
-
To make mirrors, and low melting alloys
-
To coat the bearings of high speed motors
-
Alloying for low temperature solders and fuses
-
As light filter in low-pressure sodium vapor lamps
-
Electroplating for high-performance engine components.