Properties of engineering materials

Why knowledge of material properties are so important ?

The knowledge of any engineering materials and their properties has a great importance for any engineer or you can say mechanical engineer. For designing any product, any design engineer mast have to select proper material and for selecting the material which are suitable for their designing, they must know about the properties and the correspondence characteristics of the material. When a design engineer becomes fully familiar with the properties and characteristics of the material then he/she can make the product very useful and vital for the use. They can simply create a well behaved and worthy product by the knowledge of material properties. So here in this article we are going to discuss about some of very important properties of engineering materials which must be known by an engineer.

The important mechanical properties of materials are as follows :-

Strength

Strength is that property of engineering material which can be defined as the the ability of material to resist or withstand externally applied forces without having breakdown or yielding.
The capacity of bearing load by the metal and to withstand destruction or abruption under the action of external load is called “strength.”
The stronger the material the greater the load it can bear or withstand. Thus this property of material determines the ability of material to withstand any stress without failure.
The maximum stress that any material can with stand before fracture is known as kids ultimate strength.

Elasticity

Elasticity is defined as the property of engineering material to regain or restore its original safe after the deformations when the external forces are taken off.
It is also called tangible property of material.
This property is desirable for materials used in tools and machines.

Plasticity

Plasticity is defined as the property of engineering material that retains the deformation produced under the loading permanently the plasticity property of material is necessary for forgings, stamping images on coins and also ornamental works.
It is basically the ability or tendency of the material to undergo some amount of permanent deformation without any kind of rupture or failure. Plastic deformation can happen only after the elastic limit of material exceeded.

Ductility

Ductility is dead property of engineering material by virtue of which kam material enabling it to be drawn into wires with the application of tensile force.
A ductile material must be strong and plastic. The ductility is usually measured by the terms, percentage elongation, and percent reduction in area which is often used as empirical measures of ductility.
The ductile materials commonly used in engineering practice are mild steel, copper, aluminium, nickel, zinc, tin, lead etc.

Malleability

Malleability is the ability of material to be flattened into thin sheets under the application of highly compressive forces without having cracked or tear off.
It is a special case of ductility which permits materials to be rolled or hammered into thin sheets. A malleable material should be plastic but it is not essential to be so strong.
Some of the malleable materials which are commonly used in engineering practice are lead, wrought iron, soft steel, cooper, aluminium etc.

Brittleness

We can say that Britain is that property of a material which is completely opposite of ductility it is the property of breaking of a material with little permanent distortion or abruption.
Brittle material are usually suited for compressive loads when they are given little amount of tensile load they can be distorted aur abrupted, without giving any kind of comprehensive indications.
Cast iron, glass, brass and ceramics some of the example of brittle materials.

Toughness

Toughness is the ability of material to absorb energy without any permanent fracture or rupture.
It is the property of material to resist fracture due to high impact loads like hammer blows.
The toughness of the material decreases when it is heated.
It is measured by the amount of energy that a unit volume of the material has absorbed after being stressed up to the point of fracture.
This property is desirable in parts subjected to shock and impact loads.

Stiffness

Stiffness is defined as the ability of material to resist or oppose the differentiation under stress. The resistance of material up to the elastic deformation or deflection is called stiffness or rigidity of material.
The modulus of elasticity is is the measure of stiffness of material.
A material that suffers slight or very less deformation under load has a high degree of stiffness or rigidity. For example, suspended beams of steel and aluminum may both be strong enough to carry the required load but the aluminum beam will “sag” or deflect further.
That means the steel beam is stiffer or more rigid than an aluminum beam. If the material behaves elastically with linear stress-strain relationship under Hooks law, its stiffness is measured by the Young’s modulus of elasticity (E).
The higher is the value of Young’s modulus, the stiffer is the material. In tensile and compressive stress, it is called modulus of stiffness or “modulus of elasticity”; in shear, the modulus of rigidity, and this is usually 40% of the value of Young’s modulus for commonly used materials; in volumetric distortion, the bulk modulus.

Resilience

It is the property of a material to absorb energy and to resist shock and impact loads. It is measure by the amount of energy absorbed per unit volume within the elastic limit. This property is essential for spring materials.
It is measured by the amount of energy absorbed per unit volume within the elastic limit.
This property is essential for spring materials.

Hardness

Hardness is the property of material by which it can cut another material.
It is one of the most important property of materials and has a very wide variety of of meanings. It possesses many different properties of material such as scratching, resistance to wear, defamation and machinability etc.
The hardness is usually expressed in in numbers which are dependent on the method of making the test.
some of the popular hardness test processes are –
(a) Brinell hardness test
(b) Rockwell hardness test,
(c) Vickers hardness test
(d) Shore scleroscope.

Creep

Creep is that property of a material by virtue of which it is subjected to a constant stress or load at high temperature for a long period of time by resultant of which it will undergo a slow and permanent deformation or distortion. This entire process is called “creep.”
This property is generally considered while designing internal combustion engines, boilers and turbines.

Fatigue

When a material is subjected to repeated or cyclic stresses and loads, generally it fails or ruptures below the yield point stresses. Such kind of failure is known as “fatigue.”
This failure is is caused by means of a progressive crack formation which are usually very fine and microscopic in size. This property is usually considered while designing connecting rods, springs, gears, shafts etc.

So, That was some of the important properties of engineering materials by explanations and examples. Hope you all like this content. If you are interested in such kind of valuable and interesting contents then do follow our website. Kind do share such informative contents with your friends.

FAQ – Properties of engineering materials