AdvertisemenA material can be solid, liquid, or gas. The realization of certain materials can also be changed due to the influence of temperature.In addition to grouping by shape in electrical engineering materials can also be grouped as follows.
1. Conductor Materials (conductor)
2. Insulation material (insulator / insulator)
3. Half Conductor Materials (semi-conductor)
4. Magnetic Materials.
5. Super Conductor Materials.
6. Nuclear Material.
7. Special materials (materials for making contacts, to fuse, etc.)
1. Conductor Materials (conductor) is the material that conduct electricity easily. This material has electrical conductivity (Electrical Conductivity) is large and the electrical resistance (Electrical Resistance) small. Electrically conductive material serves to drain the electrical current. Consider the function of cable, coil / winding in electrical appliance that you have encountered. Also in line transmission / distribution. In electrical engineering, conductive material that is often found is copper and aluminum.
2. Insulation material (insulator / isolator) is a material that serves to insulate (for example between 2 Conductor); to prevent the flow of electrical current leakage when both the voltage Conductor. So the insulation material must have a large resistivity and high breakdown voltage. Insulation materials are often encountered in electrical engineering are: plastic, rubber, and so forth.
3. Half Conductor Materials (Semi Conductor) is a material which has a conductivity smaller than the conductor material, but greater than the insulator material. In electronics engineering from the widely used semiconductor materials germanium (Ge) and silicon (Si). In its natural state, Ge and Si are the pelicans and an insulator material. Plant in these materials are dirt. If the material is contaminated with aluminum, the obtained P-type semiconductor material (electron-deficient materials / having a positive nature). If stained with a phosphor so that dipeoleh is N type semiconductors (electron excess materials, so that is negative). Ge has a higher conductivity than Si, while Si is more heat resistant than Ge.
4. Magnetic Materials (Magnetic Materials) are grouped into 3 groups, namely ferro magnetic, para-magnetic and he-magnetic.Ferro-magnetic materials are materials that have high permeability and easy flowing lines of magnetic force. Examples of materials that have high permeability are iron, iron sand, stalloy, and so forth.Also often found magnets which are permanent magnets, such as Alnico, cobalt, carbon steel, and so forth. Steel for the magnet is often found on plates of motor / generator, transformer plates, and so forth. In the field of electronics, magnetic materials used for example in speakers, electronic measuring instruments, and so forth.
5. Super Conductor Materials. In 1911, Onnes Kamerligh measure changes in electrical resistance caused by temperature changes Hg in liquid helium. He found that the electrical resistance suddenly disappeared at a temperature of 4.153 ° K. Until now about 24 elements have been found super conductivity and more alloys and compounds that show the properties of super conductivity. Critical temperatures ranging from 1 samapai 19 ° Kelvin. Lead materials (lead), tin (tin solder), aluminum, and mercury, in sushu approaching 0 ° K has zero resistivity.
6. Nuclear Material. Nuclear material is often used as nuclear reactor fuel. Nuclear reactor is a plane containing nuclear materials that can be split, which arranged so that a chain reaction can be run in a state and under controlled conditions. Naturally, the requirement for a material can be used as nuclear fuel is a material that can hold the fission (splitting the atom). In a nuclear reactor used uranium fuel 235, plutonium-239, uranium-233.
In the selection of electrical materials, in addition to electrical properties, to consider some other properties of materials, namely:
A. Mechanical properties, namely changes in the form of a solid body caused by external forces acting on the object. So the change was dependent on the size of the force, shape objects, and from what material the object is created.
If there is no external force acting, then there are three possibilities that would occur on an object:
• The object will return to original form, this is because the object has a rubbery properties (elastic)
• Form objects will in part be returned to original form, this is only partially able to return to their original form because of the forces acting beyond the elasticity limit so that the properties of elasticity is reduced.
• Shape object changed at all, this can happen because of the work force far beyond the elasticity limit so that the nature of resilience at all lost.
B. Physical Properties, solid objects have a fixed form (the form itself), where the temperature remains solid objects have a fixed content as well. Content will grow or expand if it had passed all the temperature and vice versa object will shrink when the temperature decreases. Because the weight of the object fixed, the density of objects will increase, so it can be concluded as follows:
• If the contents (volume) increases (expands), then the density will decrease
• If the contents decrease (shrinking), then the density will increase
• So the object is more dense in cold conditions than in hot conditions
C. Chemical properties, rust is including the chemical properties of a material made of metal. This happens because the chemical reaction of the material itself with its surroundings or the material itself with the liquid ingredients. Usually, chemical reactions with liquid material that is called rust or corrosion. While the chemical reaction with surrounding called blurring.
Testing mechanical properties of materials necessary to obtain information on material specifications. Tensile test will be obtained through the magnitudes of tensile strength, elongation strength, elongation, reduction in cross section, elastic modulus, resilient, tough metal, and others. In addition to these properties with a not too technical, need to be considered violence (hardness) and the ability to resist scratches (abrasion). Examples of physical characteristics that are often required are density, melting point, boiling point, freezing point, melting heat, and so forth. Also the nature of changes in volume, shape, and length to changes in temperature. Perkaratan are examples of material properties due to chemical reactions, the reaction between the metal with oxygen in the air. Chemical properties also include the toxic properties of materials, the possibility of undertaking the reaction with salts, acids and alkalis.
In addition to sealing or insulating material above, there are other materials that are also widely used in electrical power engineering or conductive material that is often referred to as conductors. An electrical materials that will be the Conductor, also must have the fat-Conductor nature itself such as: temperature coefficient of resistance, thermal conductivity, tensile strength and others.
Besides, Conductor mostly using solid forms such as copper, aluminum, steel, zinc, tin, and others. For the purposes of communication are now widely used conductive materials for telecommunications transmission media that is using fiber optics.
Closely related to the purposes of generating electrical energy, which is a magnetic material that will serve as a medium for energy conversion, either from electrical energy into mechanical energy, mechanical energy into electrical energy, electrical energy into heat energy or light, or from electrical energy into electrical energyagain. This magnetic material would have to satisfy the properties of magnetism, and the parameters to serve as a good magnetic material. In the selection of magnetic materials can be grouped into three kinds, namely ferromagnetic, paramagnetic, and diamagnetik.
A material that is more trendy and most research is being done in the world of science and technology of semiconductor materials.The development of electronics and computer world today is one of the role of semi-conductor technology. This material is very big role at this point in various fields of science discipline, especially in the field of electrical engineering such as information technology, computers, electronics, telecommunications, and others. In connection with semiconductor material, at this point can be grouped into two kinds of semi-conductors and super conductors.