Tuesday, 23 May 2017

18 Mechanical Properties Which Every Mechanical Engineer Should Know

Material selection for any product is main part of a manufacturing industries. The quality of product is highly depends upon its material properties. These properties are used to distinguish materials from each other. 

For Example: 

A harder material is used to make tools.

A ductile material is used to draw wires

So the knowledge of mechanical properties of material is desirable for any mechanical student or for any person belongs to mechanical industries. This article brings top 18 mechanical properties. I hope you will like it.

18 Mechanical Properties Which Every Mechanical Engineer Should Know


Mechanical properties of material:



There are mainly two types of materials. First one is metal and other one is non metals. Metals are classified into two types : Ferrous metals and Non-ferrous metals.

Ferrous metals mainly consist iron with comparatively small addition of other materials. It includes iron and its alloy such as cast iron, steel, HSS etc. Ferrous metals are widely used in mechanical industries for its various advantages.

Nonferrous metals contain little or no iron. It includes aluminum, magnesium, copper, zinc etc.

Most Mechanical properties are associated with metals. These are


#1. Strength:

The ability of material to withstand load without failure is known as strength. If a material can bear more load, it means it has more strength. Strength of any material mainly depends on type of loading and deformation before fracture. According to loading types, strength can be classified into three types.

a. Tensile strength:
b. Compressive strength:
3. Shear strength:

According to the deformation before fracture, strength can be classified into three types.

a. Elastic strength:
b. Yield strength:
c. Ultimate strength:

#2. Homogeneity:

If a material has same properties throughout its geometry, known as homogeneous material and the property is known as homogeneity. It is an ideal situation but practically no material is homogeneous.

#3. Isotropy:

A material which has same elastic properties along its all loading direction known as isotropic material.

#4. Anisotropy:

A material which exhibits different elastic properties in different loading direction known as an-isotropic material.

#5. Elasticity:

If a material regain its original dimension after removal of load, it is known as elastic material and the property by virtue of which it regains its original shape is known as elasticity.

Every material possess some elasticity. It is measure as the ratio of stress to strain under elastic limit.

#6. Plasticity:

The ability of material to undergo some degree of permanent deformation without failure after removal of load is known as plasticity. This property is used for shaping material by metal working. It is mainly depends on temperature and elastic strength of material.

#7. Ductility:

Ductility is a property by virtue of which metal can be drawn into wires. It can also define as a property which permits permanent deformation before fracture under tensile loading. The amount of permanent deformation (measure in percentage elongation) decides either the material is ductile or not.

Percentage elongation = (Final Gauge Length – Original Gauge Length )*100/ Original Gauge Length

If the percentage elongation is greater than 5% in a gauge length 50 mm, the material is ductile and if it less than 5% it is not.

#8. Brittleness:

Brittleness is a property by virtue of which, a material will fail under loading without significant change in dimension. Glass and cast iron are well known brittle materials.

#9. Stiffness:

The ability of material to resist elastic deformation or deflection during loading, known as stiffness.  A material which offers small change in dimension during loading is more stiffer. For example steel is stiffer than aluminum.

#10. Hardness:

The property of a material to resist penetration is known as hardness. It is an ability to resist scratching, abrasion or cutting.

It is also define as an ability to resist fracture under point loading.

#11. Toughness:

Toughness is defined as an ability to withstand with plastic or elastic deformation without failure. It is defined as the amount of energy absorbed before actual fracture.

#12. Malleability:

A property by virtue of which a metal can flatten into thin sheets, known  as malleability. It is also define as a property which permits plastic deformation under compression loading.

#13. Machinability:

A property by virtue of which a material can be cut easily.

#14. Damping:

The ability of metal to dissipate the energy of vibration or cyclic stress is called damping. Cast iron has good damping property, that’s why most of machines body made by cast iron.

#15. Creep:

The slow and progressive change in dimension of a material under influence of its safe working stress for long time is known as creep. Creep is mainly depend on time and temperature. The maximum amount of stress under which a material withstand during infinite time is known as creep strength.

#16. Resilience:

The amount of energy absorb under elastic limit during loading is called resilience. The maximum amount of the energy absorb under elastic limit is called proof resilience.  

#17. Fatigue Strength:

The failure of a work piece under cyclic load or repeated load below its ultimate limit is known as fatigue. The maximum amount of cyclic load which a work piece can bear for infinite number of cycle is called fatigue strength. Fatigue strength is also depend on work piece shape, geometry, surface finish etc.

#18. Embrittlement:

The loss of ductility of a metal caused by physical or chemical changes, which make it brittle, is called embrittlement.


This is all about mechanical properties of material. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it with your friends. Subscribe our website for more interesting articles.
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Monday, 22 May 2017

Top 5 Fastest Car in the World

Every car lover wants to drive a fastest car. Cars is always an interesting topic on which we want to discuss. Often we like cars because of its speed and cool looks. Today I am going to tell you about top five coolest and fastest cars with their cool pics. I hope after reading this article, you want to ride one of them.  


Top 5 Fastest Cars in the World:


5. Porsche 9ff GT9-R:

Overview:
Engine type      : Flat 6 cylinder turbocharged engine
Acceleration      : 100km/h in just 2.9 seconds
Power              : 1105 bhp at 8150rpm
Torque             : 1050 Nm at 6170rpm
Displacement    : 4000cc

Top speed : 413 km/h (256.68 mph)

Top 5 Fastest Car in The World 2014

4. SSC Ultimate Aero:

Overview:
Engine type      : SSC Designed Billet Aluminum V8 engine
Acceleration      : 96.56km/h in just 2.78 seconds
Power              : 1287 bhp at 6075 rpm
Torque             :1508 Nm at 6150 rpm
Displacement    : 6350cc

Top speed : 414.26 km/h (257.41 mph)

Top 5 Fastest Car in The World 2014

3. Koenigsegg Agera R:

Overview:
Engine type      : Koenigsegg aluminum 5.0L V8, 4 valves per cylinder, DOHC
Acceleration      : 100 km/h in just 2.8 seconds
Power              : 1140 bhp at 7100 rpm
Torque             : 1000 Nm at 2700 to 7300 rpm 
Displacement    :5000cc

Top speed : 418.43 km/h (260 mph)

Top 5 Fastest Car in The World 2014

2. Bugatti Veyron Super Sport:

Overview:
Acceleration      : 80km/h in just 2.2 seconds
Power              : 1183 bhp at 6400 rpm
Torque             : 1500 Nm at 3000 rpm
Displacement    : 8000cc

Top speed : 434 km/h (269.08 mph)

Top 5 Fastest Car in The World 2014

1. Hennessey Venom GT:

Overview:
Engine type      : 90-degree V8 engine
Acceleration      : 100km/h in just 2.7 sec.
Power              : 1244 bhp at 6600 rpm
Torque             : 1566 lNm at 4400 rpm
Displacement    : 7000 cc

Top speed          : 435.31 km/h (270.49 mph)
Projected speed : 447.4 km/h (278 mph)

Top 5 Fastest Car in The World 2014


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Sunday, 21 May 2017

Different Cutting Tool Materials

Today we will discuss about most common cutting tool materials used in mechanical industries. Tool play very important role in machining. The shape of work piece, its surface finish and some other properties are directly dependable on the tool material and its design. A proper designed tool with appropriate material gives better surface finish and high accuracy. Most important characteristic of tool are:

  • It should have high hot hardness.
  • High Wear Resistance.
  • Tool should have high Toughness and hardness.
  • It should have high thermal conductivity.
  • Tool works at high temperature during cutting so it should have low coefficient of thermal expansion.
  • Tool should have high strength.
  • It should have Low coefficient of friction and should be chemically stable.

Different Cutting Tool Materials

Cutting Tool Materials:


Most common engineering materials used in tool making are:

Carbon Steel Tool:

Carbon Steel is widely used for machining soft materials like, Magnesium, Aluminum, Wood etc. It contains carbon, silicon and magnesium as its constitute.  This material used for making hand drills narrow blade, taps, dies, chisels etc. Its cutting speed is about 10 m\mm and highest temperature up to which it can work is 200 – 250 degree centigrade.

High Speed Steel (HSS):

High speed steel is very common tool material which is an alloy of steel tungsten, Chromium and Vanadium. It contains 18% Tungsten, 4% Chromium and 1% Vanadium. This material is deep hardening and can be quenched in oil, air or salt. It has highest toughness. Its cutting speed is about 30 – 50 m\mm. It can work up to 650 degree centigrade.  

According to the composition of material, it can be divided into two major types.

1. Tungsten type steels in which tungsten is used as the major alloying element.
2. Molybdenum type steel in which tungsten is partially or completely replaced by molybdenum. It is cheaper than tungsten type steel and has greater toughness at the same level of hardness.

Stellite:

Stellite is a non ferrous alloy with cobalt, chromium, Tungsten, with molybdenum and boron. Cobalt is used about 38 – 53 percent, chromium is 30 – 33 percent, tungsten is about 10 – 20 percent and carbon contain is about 1 – 3 percent. This material has intermediate properties between HSS and cemented carbide.  Its cutting speed is about 50 – 80 m\mm. Its highest working temperature is about 900 degree centigrade.

This tool material is mostly used for rough machining at relatively high speed and feed rate and it can machine more difficult materials such as high tensile steel, stainless steels and heat treated resistant steels.

Cemented Carbide Tool:

It is made by powder metallurgy technique.  In this material, cobalt acts as binding material. These material can be divided into three types.

1. Straight tungsten carbide with cobalt as a binder.
2. Tungsten carbide with cobalt as a binder and having large percentages of carbides of titanium, tantalum, niobium and columbium etc.
3. Titanium carbide with nickel or molybdenum as the binding material.

Its highest speed up to which it can work is about 60-200 m\mm and its working temperature limit is up to 1000-1200 degree centigrade.

All carbides when finished are extremely brittle and weak in their resistance to impact and shock loading. That’s why vibrations are very harmful for carbide tools.

Ceramics:

This tool is combination of silicon carbide and aluminum oxide. It is also made by powder metallurgy.  It cannot work at low speed. This tool material has very high abrasion resistance and hard compare to cemented carbide tool. It is particularly used for machining cast iron and high tensile steel with higher cutting speed compare to cemented carbide tool.  Its highest working temperature is about 1400 degree centigrade. Its cutting speed is about 300 – 600 m\mm.

Cermets:

Combination of ceramic with metal is known as cermets. This material has high refractoriness of ceramics and high toughness and thermal shock resistance of metal. The usual combination is aluminium oxide with metal (W, Mo, Boron, Ti etc.) in an amount of 10 percent.

Diamond

Diamond is a highest known hard tool material on the earth. It has good thermal conductivity, low thermal expansion and low friction coefficient. It's cutting speed is about 1500 - 2000 m\mm. It is used for machining hard material like hard carbide, nitrides etc. It is mostly used to machining nonferrous material. 

Cubic Boron Nitride

It is the second hardest material after diamond. It is not a natural material. It consists of atoms of nitrogen and boron. This has high hardness and high thermal conductivity. CBN is chemically inert and is used as a substitute of diamond for machining steel. It is mostly used as abrasive in grinding wheel.  Its highest cutting speed is about 600 – 800 m\mm.  

UCON:

It is a new cutting material. It constitute are columbium 50 percent, titanium 30% and tungsten 20%. This has high hardness, high toughness and excellent shock resistance. It is mainly used for steel cutting material and not suitable for cutting cast iron, stainless steel and super alloys containing Ni, Co and Ti as base material. UCON gives 60 percent increases in cutting speed when compared with tungsten carbide.

Coronite:

It is a new cutting material whose properties lies in between those of HSS and cemented carbide. This material consists of fine grain of TiCN evenly dispersed in a material of heat treatable steel. It is used for producing small and medium size drill and milling cutters. It is also used for compounding and coating technology. It is mainly used as core material for HSS or spring steel.


This is all about most common cutting tool materials used in mechanical industries. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it on your social networks. Subscribe our website for more informative articles. 
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Saturday, 20 May 2017

Broaching Operation : Principle, Tools, Types, Advantages and Disadvantages

Broaching is a machining process with a special designed multi point cutting tool called broach. This process is widely used in automobile industries for machining various holes, key ways, gears etc. Broaching operation involves linear motion of tool about the work piece. This movement of tool removes material from work piece and provides a desired shape.

Broaching tools involve a large number of progressive teeth which make this operation different from other process. Each tooth takes off a successive layer of the material which removes large material in a single pass. 

One of the major advantages of using this operation in various industries is its ability to give better surface finish and good accuracy with mass production rate. In this article we will discuss about broaching operation Principle, tools, types, advantages and disadvantages.


Let's start the discussion.


Broaching Process:


Principle and Operation:

As we discussed the metal removal process in broaching operation is similar to shaping process except it uses a series of progressive teeth which can cut more material in a single pass. Shaping process requires number of strokes to cut required width of work piece in which each stroke removes a thin layer of metal. This process needs more time which is not beneficial. This limitation is taken off by broaching process by providing a successive series of cutting edges on a rod or bar type cutter. 

Broaching Operation : Principle, Tools, Types, Advantages and Disadvantages

Machine Tool:

Broaching uses a multi point cutting tool having a series of progressive cutting teeth. This tool should have high strength, hardness, cutting speed and wear resistance properties. It is made by high strength tooling material like high speed steel, cemented carbide etc.  This tool is mounted on broaching machine.


Broaching Operation : Principle, Tools, Types, Advantages and Disadvantages
Broaching Tool

Broaching machine is simple in construction. It is used to provide linear motion of the tool and hold the work piece at stationary position. The tool movement can be either vertically or horizontally. According to it, these machines can be classified into two type vertical machine and horizontal machine. Horizontal machine is mostly used for internal machining and vertical machines are used for external and surface machining.

Broaching Operation : Principle, Tools, Types, Advantages and Disadvantages

Types:

Broaching can be classified into following types:

Internal Broaching: 
Internal broaching is mainly used to enlarge holes. This process generally uses pull type broach but for lighter work piece, it sometime uses push type broach.

External Broaching:
External broaching is mainly used to flattening of a surface, machining key ways, slots, grooves on outer part of an object such as shaft etc. This process is also used for gear manufacturing process.

Pull Types Broaching:
A broach which is subjected to tensile force during machining, called pull broach and the type of broaching operation by pull broach is known as pull broaching. This operation prevents misalignment and buckling. The pull broach is usually made in single piece and used for internal broaching.

Push Type Broaching:
Push type broach is usually subjected to compression force during machining. These are made shorter compare to pull type broach and mostly used for external broaching.  

Ordinary Cut Broaching:
Ordinary cut broaching uses ordinary broach in which teeth increases in height gradually from tooth to tooth along length of broach.

Progressive Cut Broaching:
In progressive cut broaching teeth increase in width instead of height along length of the broach.

Solid, Section and Modular Broaching:
Solid broaches are made in single piece which are mostly used for internal broaching. Sectional broaches are made in section by assembling various section of broach. Module broaches are made by various modules assembled in a single unit. It is used for external broaching.

Advantages and Disadvantages:

Advantages:                                                                              
  • High production rate because whole amount of metal is removed in single stroke.
  • High surface finish and better accuracy.
  • Broaching can be used for both internal and external machining.
  • Broaching machines are simple in design and construction.
  • It can be used for mass production.
Disadvantages:
  • High tool cost.
  • This process needs a special design tool for each process.
  • This is not suitable for small batch production.
  • It is only suitable for machining holes and flat surfaces.

This is all about broaching operation, tools, types, advantages and disadvantages. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it. Subscribe our website for more informative articles.
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Tuesday, 16 May 2017

Buffing : An Ideal Process for Car Finishing

Do you have a Car?

Are you wondering? Why I am asking this silly question while talking about "buffing"?

The answer is quite simple because If you have a own car and you had took it for remove scratches, you have definitely heard this word “Buffing”.

Buffing is a surface finishing operation or more appropriate we can say it is a polishing operation used for producing mirror like image. This process gives very satisfactory result at low cost that’s why it is used in many industries.

The most common applications of buffing are automobiles, motor cycles, boats, bicycles, sporting items, tools, store fixtures, commercial and residential hardware, household utensils and appliances and much more.

Learn more about buffing process in this articles.


Buffing : An Ideal Car Finishing Process


Buffing is a polishing operation in which the work piece is brought in contact with a revolving cloth buffing wheel, which is charged with fine abrasive particles like aluminum oxide or silicon carbide. The cloth work as transporting medium for fine abrasive particle and the metal removed during rubbing action between work piece and buffing wheel.  This metal removal process removes scratch or other suspended marks from the metal body and provides a mirror like surface finish.

Buffing : An Ideal Process for Car Finishing

Mostly buffing wheel is made by linen, cotton, broad cloth and canvass. This wheel made by multiple layers of these cloths overlapped on each other. The wheel rotates during buffing operation at a speed of 32.5 -40 m/s and a small pressure applied on the wheel which promote abrasive action and removes metal in form of microchips.

Buffing is mostly used to remove only fine scratches or to remove oxide or similar coatings which may be on the work surface. Mostly buffing is done manually but semi-automatic and automatic buffing machines are also available which are used for mass production in various industries. But for complex work pieces manual buffing is most suitable in which a rotating wheel is used to buff a stationary work piece.

This is all about buffing process. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it on social networks. Subscribe our website for more informative articles.
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Monday, 15 May 2017

Lapping Process : Principle, Types and Advantages

Today we will discuss about Lapping. Lapping is a super finishing process used to create flat surfaces. It is an oldest method to obtain extreme dimensional accurate surface. It this process, two mating surfaces are rubbed together with an abrasive between them. It will remove small amount of metal in form of microchips. It is mainly used to produce close fit of mating surfaces. Honing is mainly used to finish cylindrical hollow section while lapping is used for finish flat surfaces.

Lapping is a follow up process after grinding and used for create high accurate finish surface. This process is similar to grinding except it uses loose abrasive particle to remove instead of bonded material like grinding wheel. It usually removes 0.03. – 0.003 mm from work piece.

Learn more about what is lapping process, its principle, types, advantages and disadvantages in this articles. 



Lapping Process:

Principle:

The metal removal principle in lapping is same as other metal finishing process. The metal is removed due to abrasion action of abrasive particles.

Lapping Process : Principle, Types and Advantages

This process uses a lapping plate. This plate is made by cast iron. Sometime other soft material like copper, brass etc. is used for it. The abrasive particles placed between work piece and lapping plate in form of oil mixed slurry or gel. This oil or other paste used as transporting medium for abrasive particle, avoid heating and also provide transporting medium for removed micro chips. The lapping plate remains stationary in hand lapping and rotates at a speed of 10 – 150 rpm in machine lapping. The work piece is allowed to do reciprocating motion over lapping plate which removes the material in form of microchips. During this rubbing action a pressure of about 3 pound per square inch should maintain between these two part which allow proper rubbing action.  It can achieve dimensional tolerance on the order of 0.0004 mm.


Types:

The Rubbing action in lapping can be done manually or by use of machine. According to it, lapping can be divided into two types.

Hand Lapping:
In hand lapping process, the work piece is rubbed over the lapping plate manually. In this process first the plate is coated with the abrasive material which in in the form of paste. Now the work piece is rubbed over plate by applying a small pressure manually.

Lapping Process : Principle, Types, Advantages and Disadvantages


Machine Lapping:
It is used for finish large quantity of similar parts. This machine involves a rotating lapping plate and conditional rings. Conditional rings provide sits for work piece. This rings rotate and rubbed the work piece against lapping plate. Abrasive particles are provided with suitable medium like liquid or in powder form. This rubbing removes metal in form of microchips and provide super finishing.

Lapping Process : Principle, Types, Advantages and Disadvantages

Advantages:

  • It can finish every material irrespective its hardness.
  • Size and shape is no limit of lapping process.
  • High accuracy can obtain. 

This is all about lapping process, its types, advantages and disadvantages. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it with your friends. Subscribe our website for more informative articles.
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Sunday, 14 May 2017

What is Honing, its Process Parameter, Types and its Advantages?

Accuracy of any machine part or a product is most common concern for engineers. They continuously works for develop those technologies which provide a highly accurate part with minimum tolerance. Honing is one of these processes which is used for provide better surface finish and highly accurate work piece. It is a finishing or we can say super-finishing process used for finishing round holes by means of an abrasive material.

What is Honing, its Process Parameter, Types and its Advantages?


This process uses a cylindrical mandrel dressed with an abrasive material like aluminium oxide, silicon carbide, diamond etc. This tool is called hone. This tool carried out a combined rotary and reciprocating motion to remove material at whole length of stationary work piece. The tool rotates at its own axis and reciprocates in the cylindrical hole to cover whole length of work piece. Mainly honing is considered as follow up process after drilling or boring. Sometimes it is used for finishing external surfaces. 

Learn more about what is honing its process parameters, types along with its advantages in this article. 


What is honing?


Honing can be considered as a machining process because it involves metal removal in form of microchips. The word “Honing” is developed by the word “Hone”. Hone is used for a cylindrical tool dressed with some abrasive material. This abrasive material is used in the form of sticks which are mounted on the mandrel. However nowadays diamond and carbon boron nitrite grits are used for complete the operation in just one stroke. This process is used for achieve accurate dimension of cylindrical holes. It is best suited for finishing engine cylinder. Sometimes It is used for finishing gear where tool made with plastic impregnated with abrasive.

What is Honing, its Process Parameter, Types and its Advantages?

In honing process a well-dressed (with abrasive particles) cylindrical tool rotates at its own axis. The tool diameter is almost equal to the work piece internal diameter. This tool rotates at its own axis and also reciprocates which allows to remove material in form of microchips. It can achieve tolerance of about  0.25 – 1.5 micron. This cutting form a cross lay hatched pattern at work piece.
What is Honing, its Process Parameter, Types and its Advantages?
Honing Process

The accuracy and surface finish of hole is mainly depends on various process parameter which are describe below. 

Process Parameters:


RPM of tool:
If the tool speed increases, it increases metal removal rate and decreases surface roughness.

What is Honing, its Process Parameter, Types and its Advantages?


Honing time:
If we increase honing time it will decrease surface roughness at some extent and then starts increases it. It is so selected which gives minimum surface roughness with maximum metal removal rate.

What is Honing, its Process Parameter, Types and its Advantages?


Honing stick pressure:

The change in metal removal rate and surface roughness with the change in unit pressure is shown in the graph. The honing stick pressure is so selected as to get minimum roughness with highest metal removal rate.

What is Honing, its Process Parameter, Types and its Advantages?


Stroke Length:
The stroke length should be as enough which can cover the whole working length.


Types:

Honing can be classified into two types.

Manual Honing:

In this type of honing the hone rotate continuously and the work piece is move front and back manually. This process is rarely used now days

Machine Honing:

The honing process in which the hone performs combined rotary and reciprocating motion and there is less manual interaction called machine honing. According to the type of machine this process can be classified into two types

1. Vertical honing
2. Horizontal honing


Advantages:

  • Less complex or low cost fixtures.
  • It is highly accurate.
  • It can be used for both long and short bores.
  • It maintains original bore centerline.
  • Any material can be finished regardless its hardness.

This is all about honing process, its working, types, process parameters and its advantages. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it on social network. Subscribe our website for more informative articles.
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