What is malleability

What is malleability?

Answer :

• Malleability is defined as the ability of a material to deform to a greater extent before the sign of a crack, when it is subjected to a compressive force.

Malleability comes from a word from a hammer.

What is toughness

What is toughness?

Answer :

• Toughness is defined as the ability of the material to absorb energy before fracture takes place.

Toughness is the energy for failure by fracture.

Toughness is important for machine components which are required to withstand impact loads.

Toughness is measured by a quantity called modulus of toughness.

What is resilience

What is resilience?

Answer :

• Resilience is defined as the ability of the material to absorb energy when deformed elastically and to release this energy when unloaded.

A resilient material absorbs energy within elastic range without any permanent deformation.

Resilience is measured by a quantity called modulus of resilience.

What is stiffness

What is stiffness :

Answer

• Stiffness is defined as the ability of the material to resist deformation under the action of eternal load.

All materials are deform when they are stressed, to a more or less extent.

Stiffness is also called like rigidity.

What is plasticity

What is plasticity :

Answer 

• Plasticity us defined as the ability of the material to retain the deformation produced under the load on a permanent basis.

What is elasticity

What is elasticity :

Answer 

• Elasticity is defined as the ability of the material to regain the original shape and size after the deformation, when the external forces are removed.

All the materials are elastic but the degree of elasticity is varies.

What is strength

What is strength :

Answer 

Strength is defined as the ability of the material to resist, without rupture, external forces causing various types of stresses. 

Strength is measured by different quantities.

Difference between malleability and ductility

Whenever we can talk about the property that helps the metals to deform at that time these two properties first comes to our mind. Malleability and ductility are both of them are two similar properties but they have many differences between them. 

What is Malleability?

Malleability is defined as the ability of a material to deform to a greater extent before the sign of a crack when it is subjected to a compressive force.

What is Ductility?

Ductility is defined as the ability of a material to deform to a greater extent before the sign of a crack when it is subjected to a tensile force.

Let us have a deep insight into the comparison between malleability and ductility.

Difference between malleability and ductility :

• Malleability is the ability of a material to deform under compressive force while ductility is the ability to deform under tensile force.
• All ductile materials are also malleable, but the converse of that is not true.
• Malleability increases with temperature while ductility decrease with increasing temperature.
• With hammering or rolling without fracture, a malleable material can be shaped with plastic, while ductile materials can usually be elongated with more than 15% before fracturing.
• Malleable material can be rolled into sheets while ductile can be rolled into the wire.
• Malleability is an important property when the component is forged, rolled or extruded while ductility is desirable when the components are formed or drawn and also when components are subjected to shock loads that is a good property of ductility.
• Both malleability and ductility are reduced by the presence of impurities in the metal.
• Malleable materials are mild steel, gold, lead while ductile materials are copper, mild steel and thermoplastics.
• Lead has high malleability, with low ductility.
• Malleability is affected by the crystal structure and ductility is affected by the grain size.
• Test for measured malleability is the ability to withstand pressure while ductility by the bend test.

Notes : 

Most ductile materials are malleable. 

Gold is both highly ductile and malleable that is the main reason that it is used in making jewellery. 

Malleability and ductility of metals can be accounted for due to their presence of elastic forces While malleability and ductility are both characteristics of substance with metals.

Difference between resilience and toughness

Both Resilience and toughness are discussed during the design of any components or parts of material science. They are different and although the two are closely related and the differences are significant so we can check the difference below. 

What is Resilience?

Resilience is defined as the ability of a material to absorb energy when elastically deformed and release it when unloaded.

What is Toughness?

Toughness is defined as the ability of a material to absorb energy before a fracture occurs.

Let us have a deep insight into the difference between resilience and toughness. 

Difference : 

• Resilience is the ability of the material to absorb energy within an elastic range while toughness is the ability of both the elastic and the plastic range to absorb energy.
• Modulus of resilience is the area below the stress-strain curve in the tension test up to the yield point while the modulus of toughness is the total area below the stress-strain curve.
• Resilience is essential in spring applications whereas toughness is required for components subjected to bending, twisting or impact loading components. 
• Spring steels are resilient while structural steels are tough.
• Metallic glasses are the most resilient materials, while stainless steels and titanium alloys are known to be very tough materials.

Application of plain carbon steel

Depending upon the percentage of carbon, plain carbon steels are classified into the following category :

1. Low carbon steel
2. Medium carbon steel
3. High carbon steel

Some of the important application of plain carbon steel is following below.

Applications of plain carbon steel :

1. 7C4 used for components made by severe drawing operation such as automobile bodies and hoods.
2. 10C4 used for case hardened components such as cams and cam shafts, gudgeon pin, sprocket and spindle.
3. 30C8 used for cold-formed and case hardened parts such as a socket, tie road, yoke, lever and rocker arm.
4. 40C8 used for transmission shaft, crank shaft, connecting road, bolts
5. 45C8 used for machine tool spindle, transmission shaft, bolts and gears of large dimensions
6. 50C4 used for transmission shaft,, worms, gears and cylinders.
7. 55C8 used for components with moderate wear resistance such as gears, cam, sprocket, cylinder and key.
8. 60C4 used for machine tool spindle, hardened bolt and pinion.
9. 65C6 used to make coil and leaf spring.

Difference between elasticity and plasticity

Elasticity and plasticity both of them are discussed under material science while designing any components or parts. Elasticity is a property of a material that allows it to deform reversibly and resume its normal shape after being stretched or compressed thus is a physical property. Plasticity is a property of a material that allows it to deform irreversibly thus plasticity is also a physical property of matter. Now, let us have a deep insight into the comparison between elasticity and plasticity.  

Main difference : 

The main difference between them is that elasticity causes reversible deformation of matter whereas plasticity causes irreversible deformation of matter. In polymer chemistry, elastomer show elasticity while thermoplastics shows plasticity. 

The difference between elasticity and plasticity is following below. 

• Elasticity is the ability of a metal to regain its original shape after temporary deformation under the external forces while plasticity is the ability to retain the deformation permanently even after the load is removed.
• The amount of elastic deformation is very small while there is relatively more plastic deformation. 
• Metal atoms are temporarily displaced from their original position during elastic deformation and return when the load is removed while metal atoms are permanently displaced from their original position in plastic deformation and take up new positions.
• For the majority of the material, the stress-strain relationship is linear in the elastic range while non-linear in the plastic range.
• Elasticity is an important consideration in components of machine-tool while plasticity is desirable for components made by press working operation.

Difference between carburetor and fuel injector

Carburettor and fuel injector both of them are the devices used to make a mixture of air and fuel and provide it to the engine. so the output of both the device is same but still, there is some difference between them. Let us have a deep insight into the comparison between carburettor and fuel injector. 

Difference : 

• A carburettor is a very old technology while fuel injector is newly innovative technology of an alternative of the carburettor.
• In most of the cases carburettor used in petrol engine while the fuel injector in a diesel engine.
• The carburettor is a purely mechanical device whereas fuel injector mechanical as well as the electrical device also. Nowadays it mostly used as an electrical device.
• The carburettor is required maintenance and tuning manually whereas fuel injector done that automatically because of it connect with ECU to a diagnostic device or computer.
• In automobile with carburettor also have a mechanical fuel pump whereas fuel injection has an electric fuel pump.
• A carburettor is more complex in design as compared to the fuel injector because lots of screws are needed in the carburettor.
• You have accelerated more in the carburettor and also to keep the speed constant so the loss of power is more while fuel-injector the loss of power on a climb is very less and you don't have to depress the accelerator much to keep the speed constant.
• A fuel injector is more efficient than carburettor because it is more efficiently use fuel and reduce fuel consumption and fewer emissions too.
• Carburettor working principle is also different from fuel injector but they are using for the same purpose.

Difference between soldering and brazing

Soldering and brazing, both the processes are used for the same purpose and both of them do not melt the parent material to be joined. They join by filling up micro irregularities in mating surfaces and then further fine gaps are filled by capillary action. Both of them are the metal joining process used in different joining conditions but the main difference between them is mainly the filler material composition and a melting point of that material.

Soldering filler materials are alloys of lead and tin.

The melting point of 250 to 300 ⁰C. 

Brazing filler materials are alloys of copper and tin and zinc. 

The melting point of 500 to 650 ⁰C.

From the above point, the main difference is soldering happens at a lower temperature while brazing takes place at a higher temperature. 

Both processes looked like the same they have much other difference between them. Let us have a deep insight into the comparison between soldering and brazing. 

Difference between soldering and brazing : 

• Brazed joints are stronger than the soldered joint.
• When a gap between the metals part is not a fine gap soldering is used and brazing is used to cover a fine gap between the metals part to be joined.
• No change in mechanical properties after joining while in brazing it may change in mechanical properties of joint but it is almost negligible.
• In soldering, no heat treatment is required while it is required after brazing.
• For soldering cost involved and skill, requirements are very low while in brazing cost involved and the skill required is more than soldering.
• Soldering is a softer metal joining process where the metals parts are not held very tightly while brazing creates a tight fit between the metal parts joined.
• Soldering is used for joining electronics component while brazing used in automotive industries and pipe fitting. 
• In soldering heating of the workpieces are not required while in brazing workpieces are heated but below their melting point.
• Soldering is possible only in case of thin as well as similar sheet metals while brazing is possible thicker and also similar as well as dissimilar metal parts. 

Types of fluid

The fluid may be classified into the following five types :

1. Ideal fluid
2. Real fluid
3. Newtonian fluid
4. Non-Newtonian fluid
5. Ideal plastic fluid

Ideal fluid :

Ideal fluid is a fluid which is incompressible and is having no viscosity.

Ideal fluid is only an imaginary fluid.

Real fluid :

The real fluid is a fluid which possesses viscosity.

All fluid is in actual practice is real fluid.

Newtonian fluid :

A real fluid, in which the shear stress is directly proportional to the rate of strain is known as a Newtonian fluid.

Non-Newtonian fluid :

A real fluid, in which the shear stress is not proportional to the rate of strain is known as a Newtonian fluid.

Ideal plastic fluid :

A fluid, in which shear stress is more than the yield value and shear stress is proportional to the rate of shear strain is known as ideal plastic fluid.

What is specific gravity

Specific gravity is defined as the ratio of the weight density of a fluid to the weight density of a standard fluid.

For liquid standard fluid is taken as water and for gas is air.

Specific gravity is also called relative density.

Specific gravity is a dimensionless quantity.

It denoted by S.

S ( for liquid ) = Weight density of liquid / Weight density of water

S ( for gases ) = Weight density of gas / Weight density of air

What is specific volume

A specific volume of a fluid is defined as the volume of a fluid occupied by a unit mass or volume per unit mass of a fluid is called specific volume.

Specific volume = Volume of fluid / Mass of fluid 

Specific volume is also reciprocal of mass density. 

The unit of specific volume is m³/kg.

Specific volume is mostly applied to gases.

What is specific weight

The specific weight of a fluid is the ratio between the weight of a fluid to its volume.

Specific weight is also called weight density.

Weight per unit volume of a fluid is called weight density.

It denoted by w.

w = Weight of fluid / Volume of fluid 

What is density

Density is a degree of compactness of a substance.

Density is defined as the ratio of the mass of a fluid to its volume. thus mass per unit volume of a fluid is called density.

It denoted as ρ.

ρ = Mass of fluid / Volume of fluid

The unit of density :

SI Unit : kg / cubic meter = kg/m³

The density of liquids may be considered as constant while that of gases changes with the variation of pressure and temperature.

The density of water is 1 gm/cm³ or 1000 kg/m³.

Density and viscosity both of them have a certain similarity. 
Don't get confused with each other terms. You can go to the difference between viscosity and density and clear your confusion. 

What is viscosity

Viscosity definition :

Viscosity is the property of a fluid which determines its resistance to shearing stresses.

Cause of Viscosity: 

It is due to cohesion and molecular momentum exchange between fluid layers.

Newton’s Law of Viscosity: 

It states that the shear stress (τ) on a fluid element layer is directly proportional to the rate of shear strain.

T = µ (du/dy)

Where µ = Coefficient of dynamic viscosity 

Units of Viscosity :

S.I Units : Pa.s or N.s/m²

C.G.S Unit of viscosity is Poise = dyne-sec/cm²

One Poise = 0.1 Pa.s

1/100 Poise is called centipoises.

Dynamic viscosity of water at 20 ⁰C is approx= 1 cP

Kinematic Viscosity :

Kinematic viscosity is the ratio between the dynamic viscosity and density of the fluid.

It is denoted by ν.

ν = dynamic viscosity / density 

Units of Kinematic Viscosity :

S.I units: m²/s

C.G.S units: stoke = cm²/sec

One stoke = 10^-4 m²/s

Viscosity and density are two same terms but there is a difference between them. Let we check it out the difference between viscosity and density.

Characteristics of fluid

What is fluid :

A fluid is a substance which deforms continuously when it is subjected to external shearing forces.

Characteristics of Fluid :

• It has no proper shape of its own but conforms to the shape of the containing vessel.
• A fluid can be defined unambiguously as a material that deforms continuously and permanently under the application of shearing stress, no matter how small.
• The fluid has elastic properties only under direct compression.

1. Ideal Fluid

An ideal fluid is one which has

• No viscosity
• No surface tension
• Incompressible

2. Real Fluid

A Real fluid is one which has

• Viscosity
• Surface tension
• Compressible

Naturally available all fluids are real fluid.