Disadvantages of glass reinforced plastic

Reinforced plastic has more strength and high resistance against weather, thus finding its use in outdoor applications and other many applications so it allows many advantages. Let us have a deep insight into the disadvantages of glass-reinforced plastic.

Disadvantages of glass-reinforced plastic :

• Glass-reinforced plastic has poor rigidity and stiffness.
• Glass-reinforced plastic is limited up to a temperature of 300 ⁰C.
• Glass fibre being considered as cancer-causing, it is labelled a health concern.
• Glass fibre also irritates a person's skin as well as eyes and lungs. 

Advantages of ceramics engine components over conventional metal components

• Ability to withstand higher operating temperature.
• Excellent wear and corrosion resistance.
• Lower frictional loss.
• Ability to operate without cooling system.
• Light weight construction with low inertia force.

Advantages and disadvantages of ceramics

The advantages of modern engineering ceramics are following below :

• Most of the ceramics possess high hardness due to strong covalent bonds between atoms in their crystal structure.
• Ceramics have high melting points because of this advantages it used for the lining of the furnaces.
• Ceramics are good thermal insulators hence it possess excellent insulating property.
• Ceramics have extremely high electrical resistivity hence they are used for electrical insulators.

Note : Alumina is used for spark plug insulation.

• The densities of ceramics are low as compared to other engineering material. This results in lightweight components.
• Ceramics are chemically resistance to most of the acids, alkalis and organic substances this increases durability of the ceramics components.

Disadvantages of ceramics :

• Ceramics are brittle in nature hence brittle fracture in cast iron components.
• They are highly susceptible to stress concentration.
• In ceramics ductility is almost zero because of presence of small voids in the structure of ceramics parts.
• Ceramics have poor tensile strength.
• Ceramics are difficult to shape and machine.

We will see the advantages and disadvantages of ceramics but a number of parts of automotive engines are now a days made of ceramics include cylinder liners, pistons, valves and engine blocks. 

Therefore the principle advantages of ceramics engine components over conventional metal parts are also interesting that we have to discuss.

Ergonomic consideration in design

First of all, before we go to the point where the ergonomic used in the design of the machine. We should know first what is ergonomic?

Ergonomics :

Ergonomics is defined as the relationship between man and machine and the application of anatomical and physiological to solve the problems arising from the man-machine relationship.

The word ergonomics comes from the two Greek words :

Ergon means work and Nomos means Natural laws.

So we see above Ergonomics means the natural laws of work.

In the following design concentration ergonomics study are important :

• Design of hand levers and handwheels.
• The layout of instrument dials and displays panels for accurate perception by the operators.
• Anatomical factors in the design of a driver's seat.
• Energy expenditure in hand and foot operations.
• Lighting, noise and climatic conditions in the machine environment.
• The ergonomics applied during the design phase of this door assures the easy and correct use, without any harms to the driver.

We have seen above how ergonomics must be present at all stages of development of a project. 

In short, we must emphasize the understanding and the contribution of ergonomics to the management of the design. You have considered ergonomics as part of the whole design process.

Use of standards in machine design

The following standards are used to all mechanical engineer while design a machine components.

• Standards for materials, their chemical compositions, mechanical properties and heat treatment.
• Standards for shapes and dimensions of commonly used machine elements.
• Standards for fits, tolerance and surface finish of components.
• Standards for testing of products.
• Standards for engineering drawing of components.

Mainly there are three types of standards used in design.

• Company standards

They are used in particular company or group of company.

• National standards

National standards are :

IS ( Bureau of Indian Standards ) 

DIN ( German )

AISI or SAE ( USA )

BS ( UK )

• International standard

These are prepared by the International Standards Organization ( ISO )

What is hardness

What is hardness :

Answer 

• Hardness if defined as the resistance of the material to penetration or permanent deformation.

Hardness of the material depends upon the resistance of plastic deformation.

What is brittleness

What is brittleness :

Answer 

• Brittleness is the properties of a material which shows negligible plastic deformation before fracture takes place.

Brittleness is the opposite to ductility.

What is ductility

What is ductility?

Answer 

• 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.

Ductility is a permanent strain that accompanies fracture in a tension test.

Ductility is characteristic of substances with metals.

You can also check it out: 

• Property of ductility. 

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.