Mechanical Properties of Conducting Materials

MECHANICAL PROPERTIES OF CONDUCTING MATERIALS:

 

1. Conductivity (σ) : The reciprocal of the material's electrical resistance is the conductivity (σ). Mhos/cm is the unit of conductivity. It is the property of a material that allows electric current to flow freely through it. In other words, it makes it simple for electric current to pass through the material.


2. Tensile Strength : The ability to resist load without failure is characterised as a material's strength. The ability of a material to sustain a stretching (tensile) force without fracture is referred to as tensile strength. As a result, tensile strength indicates the conductor limit, beyond which significant distortion or fracture occurs. It's measured in load per square metre of cross-sectional area. (tonnes / cm2).


3. Ductility : It refers to a material's capacity to deform plastically under tensile load without rupturing. A ductile substance can be pulled into a fine wire and bent, twisted, or modified in shape without breaking. Difficult materials include gold, silver, copper, aluminium, nickel, tin, and lead.


4. Corrosion Resistance : The electrochemical attack causes corrosion, which is a slow process in a material. The metal is generally converted into an oxide, salt, or some other compound as a result of the chemicals present in the atmosphere and if the material is exposed, the metal is generally converted into an oxide, salt, or some other compound, and thus the metal does not serve the purpose it was intended to serve. It can also happen at high temperatures in materials that are inert at room temperature or below.

 

5. Effect of Alloying on Resistivity : Resistivity is increased by any impurity, whether metallic or non-metallic. The influence of metal impurities on a metal's resistivity is determined by the type of alloy produced. When the atomic volumes and melting temperatures of the two metals differ significantly, the alloy is made up of crystals from both metals. Mechanical mixes are the name given to such alloys. In these alloys, the resistivity and temperature coefficient of resistivity fluctuate linearly with the degree of impurity content.


When the atomic volumes of the two metals differ by less than 15%, the alloy has a single crystal structure in which the atoms of both metals are accommodated by the crystal lattice. Solid solution alloy is the name for this type of alloy. With a particular level of impurity content, the resistivity increases and the temperature co-efficient falls in this type of alloy. If the impurity is increased after that, the resistivity decreases and the temperature co-efficient increases.


Chemically mixed alloys are created when metals combine chemically. The relationship between resistivity and temperature coefficient of resistivity and impurity content is intricate. The alloying increases the mechanical strength of the material and makes it harder.

 

6. Alloying Effect on Mechanical Properties: The addition of even a little amount of some alloys increases the mechanical and physical properties of the material. The following are a few of the outcomes:

(a) Copper: It improves ductility while increasing strength and hardness. Corrosion resistance is improved as well.

(b) Aluminium: It serves as a deoxidizer, slowing grain development and facilitating nitriding.

(c) Lead: It makes things easier for the machine.

(d) Nickel: It improves tensile strength while keeping ductility. The coefficient of thermal expansion is reduced as toughness increases. Reduces corrosion while increasing hardness marginally.

(e) Tungsten: A high carbide forming propensity slows grain formation and enhances cohesive force significantly.

(f) Silicon: Enhances magnetic permeability as well as electrical resistance. Increases the ability to resist oxidation. Increases ultimate strength. Assists in the strengthening of ferrite.

(g) Chromium: Strengthens and hardens without compromising ductility. Wear and corrosion resistance are improved. Improves toughness and raises the critical temperature.

(h) Manganese: Reduces the melting point of iron, lowers the critical temperature, and promotes steel hardenability.

(i) Cobalt: Enhances the toughness of high-speed steel by providing good magnetic characteristics.

 

7. Solderability : A fusible alloy named solder is used to bond metal surfaces. The property comes particularly handy when two metal objects need to be linked together, such as when wires are involved.

 

8. Brittleness: Metal tends to break when struck with a hammer, and it is the polar opposite of toughness. Shock loads are easily broken by the fragile material.

Sreejith Hrishikesan

Sreejith Hrishikesan is a ME post graduate and has been worked as an Assistant Professor in Electronics Department in KMP College of Engineering, Ernakulam. For Assignments and Projects, Whatsapp on 8289838099.

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