Engineering choice

15 [Most] Important Car Engine Parts with functions, You Must Know about it.

2020-08-30T14:37:00.006+05:30

Automobile engines are complex mechanisms that are made up of many internal parts that act as a clock to produce the power that moves your vehicle. For the engine to operate properly, all of its parts must be in good condition. One flaw can be devastating. In this article, we are learning about main important car engine parts,

Cylinder block
Cylinder
Piston
Combustion chamber
Intake manifold
Exhaust manifold
Intake and exhaust valves
Spark plug
Connecting rod
Crankshaft
Piston ring
Gudgeon pin
CamShaft
Cam
Flywheel

Cylinder Block;

Cylinder block

The cylinder block is one of the engine's central components. It plays a key role in the lubrication; temperature control and stability of the engine and it has to be of the highest quality so there is no room for short cuts.

The main structural member of all automotive engines is a cylinder block that typically extends upward from the centerline of the main support for the crankshaft to the junction with the cylinder head. The block serves as the structural structure of the engine and carries the mounting pad by which the engine is supported in the chassis.

The cylinder block of an automobile engine is a casting with mechanized surfaces and threaded holes suitable for connecting cylinder heads, main bearings, oil pans, and other units.

The crankcase is made up of a portion of the cylinder block below the cylinder block and a stamped or cast metal oil pan that forms the engine's lower enclosure and also serves as a lubricating oil repository, or sump.

The inner surface of the cylinder block, which is transported to a cylindrical shape, is called the bore or face.

A typical cylinder block unit is made up of several cylinders, based on the type and specification of the engine model, and will include cylinder walls, coolant passages, and cylinder sleeves.

Cylinder;

The cylinders are openings of the circular cross-section that extends through the upper portion of the block, with interior walls bored and polished to form smooth, accurate bearing surfaces. The cylinders of heavy-duty engines are usually fitted with removable liners made of metal, which is more resistant to wear than those used in block casting.

There are two arrangements of cylinders in common automotive use - vertical, or in-line,

As the name suggests the cylinder is cylindrical in shape. This the actual place where fuel-burning happens and piston reciprocates. A cylinder is machined with a very high surface finish. It is case hardened, to obtain a very hard scratch-free surface.

Piston;

Piston

The pistons are cup-shaped cylindrical castings of steel or aluminum alloy. The upper, closed-end, called the crown, forms the lower surface of the combustion chamber and receives the force employed by the combustion gases.

The outer surface is machined to fit the cylinder bore closely and is geared to obtain piston rings that seal the gap between the piston and the cylinder wall. In the upper piston grooves, there are plain compression rings that prevent combustion gases from the past the flow of the piston.

The lower rings are resolved to distribute and limit the amount of lubricant on the cylinder wall. Piston pin supports (bosses) are cast in opposite sides of the piston and hardened steel pins fitted into these bosses pass through the upper end of the connecting rod.

Combustion chamber;

The combustion chamber is defined by the position, size, and location of the piston within the cylinder. The bore is the inner diameter of the cylinder. The volume at the bottom dead center (VBDC) is defined as the volume occupied between the cylinder head and the piston face when the piston is farthest from the cylinder head.

The volume at the top dead center (VTDC) is the volume occupied when the piston is closest to the cylinder head; the distance between the piston face and cylinder head at VTDC is called the clearance. The distance traveled by the piston between its VTDC and VBDC locations is stroke.

The compression ratio is the most important factor affecting the theoretical efficiency of the engine cycle.

Intake manifold;

Intake Manifold

The intake manifold is the pipe that brings air or air-fuel mixture into the combustion chamber for combustion. It is connected to intake valves.

In a diesel engine intake manifold is used for providing air to the engine but in the petrol engine intake manifold is used to supply fuel-air mixture to the engine or combustion chamber.

From the construction of the above manifold, one can easily understand that is a manifold of the four-cylinder engine because it has four outlets.

Exhaust manifold;

Exhaust manifold is a pipe which takes out exhaust gases from the combustion chamber after combustion. It is connected to exhaust valves. Its construction is the same as the inlet manifold.

Exhaust manifold has the same function in both petrol and diesel engines, in both cases, it carries exhaust gas.

Intake and Exhaust valves;

Intake and exhaust valves

Inlet and exhaust valves are used to control and regulate charge (or air) coming to the engine for burning and exhaust gases going out from the cylinder respectively.

They are provided either on the cylinder heads or on cylinder walls. They commonly have a mushroom-shaped head.

In the case of Petrol engines, air and fuel mixture enters through the inlet valve, but in diesel engines, only air enters through intake valve. The exhaust valve in both the cases is meant for letting exhaust gases out.

Intake valves are connected to the intake manifold and exhaust valves are connected to exhaust manifold. Both intake and exhaust manifolds are discussed above.

Spark plug;

Spark Plug

The spark plug is an important component of the ignition system and is one that must operate under the most severe conditions. Because this combustion chamber is exposed to temperature and pressure and contaminated products of combustion, it requires more service attention and is typically the shortest-living component of a gasoline engine.

It consists of a steel shell threaded to fit a standard 14-mm hole in the head of the cylinder. Spark plugs can use a gasket or tapered seat to fit the gap between the cylinder head and the plug. A fused ceramic insulating element is molded into the plug body, and the steel center electrode passes through the insulator up to the connector to which the high-voltage lead from the distributor is attached.

The other electrode is welded to the metal body of the plug, which is mounted on the cylinder head. Electrodes are found in many configurations and are made of different types of alloys.

Connecting Rod;

Connecting rod

A forged steel-connecting rod connects the piston to the throw (offset part) of the crankshaft and converts the rotating motion of the piston to the rotational speed of the crank.

The connecting rod has two ends small end and big end. The small end is connected to the piston head with the help of a gudgeon pin and the big end is connected with the crankshaft with the help of crankpin. V-type engines typically have opposite cylinders, which are sufficiently vibrated to allow the two connecting rods to operate together at each crank throw.

Crankshaft;

Crankshaft

The crankshaft is one of the most important car engine parts. It converts the reciprocating motion of the piston to rotary motion with the help of a connecting rod. The connecting rod is the same rod discussed above and it transfers power from the piston to the crankshaft. The crankshaft has provisions for static and dynamic load balancing.

Piston rings;

Piston Ring

The piston is a major part of an IC engine. It forms a movable boundary. When fuel burns inside the cylinder, it applied a pressure force on the piston which moves it downward and converts thermal energy into mechanical energy.

Pistons are equipped with some metal rings which perform many functions. These rings are known as piston rings.

There are mainly three types of piston rings are used in the piston.

The first one is the temperature ring. This piston ring is designed to bear extreme temperatures.
The second one is a pressure ring. This piston ring is designed to bear extreme pressure due to thrust generated by the engine.
The third one is the Lubrication ring. This piston ring is designed in such a way that a small amount of lubricant always passes through it to the combustion chamber.

Gudgeon pin;

Gudgeon pin

In the car's engine, the Gudgeon pin attaches the piston to the connecting rod and gives a bearing for the connecting rod to drive the piston.

Material: Steel Alloy or Titanium Pin (Low Density) (Ti-6Al-4V)

Camshaft;

camshaft

The key parts of any camshaft are the cam lobes. As the camshaft rotates, the lobes open and close the intake and exhaust valves in time with the piston speed. It turns out that there is a direct relationship between the size of the cam lobes and the way the engine performs in different speed ranges.

Cam;

These are an integral part of camshafts. Due to cams, a camshaft is known as a camshaft. The cams are mounted on the camshaft to control inlet and exhaust valve timing.

Now, we are talking about most important car engine part.

Flywheel;

Flywheel

The torque provided by the engine is not uniform and is fluctuating in nature. If a vehicle continues to move with this fluctuating power that it will cause huge discomfort to the rider and also it will decrease the life of its different parts.

Hence to deal with the problem of fluctuating load a flywheel is used. A flywheel is generally mounted on camshaft. It stores torque when its value is high and releases it when its value is low in a cycle of operation. It acts as a torque buffer.

What is Chromium? Physical and Chamical Properties , uses and Effect on body.

2020-08-29T13:54:00.002+05:30

What Is Chromium Metal?

Chromium (Cr)

Chromium is a chemical element by the symbol Cr and atomic number 24. It is the first element in group 6. It is a steel-gray, shiny, hard, and brittle transition metal. When it burns it does not tarnish in the air and forms green chromic oxide. Chromium is uncertain in oxygen; It quickly produces a thin oxide layer that is impermeable to oxygen and protects the metal underneath.

Chromium is the principal additive in stainless steel, to which it adds anti-corrosive properties. Chromium is also highly valued as a metal that is capable to be highly polished while resisting tarnishing. Polished chromium represents approximately 70% of the visible spectrum, with approximately 90% of infrared light reflected. The name of the element is derived from the Greek word ‘chroma’, a Greek word meaning color, due to its ability to produce vivid, colorful compounds, such as chrome oxide.

What will you know after reading this article?

Who Discover Chromium and How?
Physical and Chemical Properties of Chromium.
How is chromium processed? (Production of Chromium Metal).
Uses of Chromium Element.
Use of Chromium Compounds
What are the side effects of chromium on human Health?

Who Discover Chromium?

Chromium metal was discovered by the French chemist Louis-Nicolas Vauquelin in Paris 1797.

How Was Discover Chromium?

Vauquelin discovered the element in a mineral sample of ‘Siberian red lead’- now known as crocoite (lead chromate). They boiled crushed carbonate with potassium carbonate, producing a yellow potassium salt solution of lead carbonate and chromic acid. Vauquelin was influenced by further experiments on the solution that he had found a new metal.

In 1781 he succeeded in isolating the metal. Initially, he switched the lead from the mineral sample by precipitation with hydrochloric acid. The vauquelin then obtained the oxide by evaporation and finally separated the chromium by heating the oxide in a charcoal oven. He also identified small amounts of chromium in ruby and emerald stones.

While chromium compounds have been used in dyes and paints for thousands of years, it was not until chromium used in metal use began to develop after the discovery of Voegelin. In the late 19th and early 20th centuries, metallurgists in Europe were actively experimenting with metal alloys, trying to produce stronger and more durable steel.

In 1912, while working at Firth Brown Laboratories in the UK, metallurgist Harry Brearley was tasked with finding a more resilient metal for gun barrels. They added chromium, a higher melting point to traditional carbon steel, which previously produced stainless steel. However, at about the same time, others, including Elwood Haynes in the US and engineers at Krupp in Germany, were also developing chromium containing steel alloys. With the development of the electric arc furnace, large-scale production of stainless steel followed shortly after that.

During the same period, research was also being done on electro-plating metals, which allowed cheaper metals, such as iron and nickel, to adopt onto their exterior chromium's resistance to abrasion and corrosion, as well as its aesthetic qualities. The first chrome feature appeared on cars and high-end watches in the late 1920s.

Physical and Chemical Properties of Chromium.

Physical properties

Chromium is a hard, steel-gray, shiny, metal that cracks easily. It has a melting point of 1,900°C (3,450°F) and a boiling point of 2,642°C (4,788°F). The density is 7.1 grams per cubic centimeter. One important property is that chromium can be polished to a high shine.

Chemical properties

Chromium is a fairly active metal. It does not react with water but reacts with most acids. It combines with oxygen at room temperature to form chromium oxide (Cr 2 O 3). Chromium oxide forms a thin layer on the metal surface, protecting it from further corrosion.

How is chromium processed? (Production of Chromium Metal)

Industrial chromium products include chromium metals, ferrochrome, chromium chemicals, and foundry sand. In recent years, there has been a trend towards greater vertical integration in chromium material production. That is, more companies are involved in the mining of chromite ore are also processing it into chromium metal, ferrochrome, and, ultimately, stainless steel.

The primary mineral extracted for chromium production in 2010 was 25 million tons in the global production of chromite ore (FeCr2O4). Production of ferrochrome was around 7 million tons, while chromium metal production was about 40,000 tons. Pheochromium is produced using fully electric arc furnaces, while chromium metal can be produced through electrolytic, silico-thermic, and aluminothermic methods.

During the production of ferrochrome, the heat created by electric arc furnaces, which reaches 5070°F (2800°C), causes coal and coke to reduce chromium ore through a carbothermic reaction. Once sufficient material has been smelted in the furnace hearth, the molten metal is drained out and solidified in large castings before being crushed.

Aluminithmic production of high purity chromium metal exceeds 95% chromium metal produced today. The first step in this process requires that the chromite ore is roasted with soda and lime in the air at 2000°F (1000°C), which creates sodium chromate containing calcine. It can be removed from the waste material and then reduced to chromic oxide (Cr2O3).

The chromic oxide is then mixed with powdered aluminum and put into a large clay crucible. Barium peroxide and magnesium powder are then spread onto the mixture, and the crucible is surrounded by sand (which acts as insulation).

The mixture is ignited, resulting in the oxygen from the chromic oxide reacting with the aluminum to produce aluminum oxide and, thereby, liberating molten chromium metal that is 97-99% pure.

Uses of Chromium Element:

The following are the application areas of chromium:

Chromium surfaces are formed by electrochemical and chroming on other metals.
There are two types of electroplating: decorative and “hard.” The decorative plate varies between 0.000254 and 0.000508 millimeters (0.00001 and 0.00002 inches) in thickness and is usually deposited over nickel.
"Hard" plating is used because of its wear resistance and low coefficient of friction. For this type of plating, a solution of chromic acid (CrO3) is used.
Chromium is added to cobalt alloys in quantities of up to 25 percent to obtain corrosion resistance and hardness. Cobalt – chromium – tungsten alloys are used for cutting tools and hard facing.
Nickel-chromium superalloys with up to 60 percent chromium and sometimes a little iron is used for high-temperature applications. Chromium is also added to aluminum alloys in amounts up to 0.5 percent to improve their strength and corrosion resistance.
The metal is also widely used as a catalyst in dyeing and tanning of leather
Chromium compounds are used as industrial catalysts and pigments (in bright green, yellow, red, and orange colors). Rubies get their red color from chromium, and glass treated with chromium has an emerald green color.
To manufacture molds for the firing of bricks
Chromium is a required trace element for humans because it helps us to use glucose. However, it is poisonous in excess. We take in about 1 milligram a day. Foods such as brewer’s yeast, wheat germ, and kidney are rich in chromium.

Use of Chromium Compounds

Chromium compounds have many different uses. Some include:

chromic fluoride (CrF 3): printing, dyeing, and mothproofing woolen cloth
chromic oxide (Cr 2 O 3): a green pigment (coloring agent) in paint, asphalt roofing, and ceramic materials; refractory bricks; abrasive
chromic sulfate (Cr 2 (SO 4) 3): a green pigment in paint, ceramics, glazes, varnishes, and inks; chrome plating
chromium boride (CrB): refractory; a high-temperature electrical conductor
chromium dioxide (CrO 2): covering for magnetic tapes ("chromium" tapes)
chromium hexacarbonyl (Cr (CO) 6): catalyst; gasoline additive

What are the side effects of chromium on human Health?

People can be exposed to chromium through breathing, eating or drinking, and skin contact with chromium or chromium compounds. Chromium levels in air and water are usually low. In drinking water, the level of chromium is usually low as well, but contaminated well water may contain the dangerous hexavalent chromium.

For most people eating food that contains chromium is the main route of chromium uptake, as chromium occurs naturally in many vegetables, fruits, meats, yeasts, and grains. Different methods of food products and storage can change the chromium content of the food. Food may increase when stores in steel tanks or compartment chromium concentrations.

Chromium is an essential nutrient for humans and shortages may cause heart conditions, disruptions of metabolisms, and diabetes. But the uptake of too much chromium can cause health effects as well, for instance, skin rashes.

chromium is a threat to human health, mainly to people who work in the steel and textile industries. People who consume tobacco are more likely to be exposed to chromium.

Chromium is known to cause various health effects. When it is a compound in leather products, it can cause allergic effects, such as skin rashes. After breathing it in chromium can cause nose irritations and nosebleeds.

Other health problems that are caused by chromium are:

Skin rashes
Upset stomachs and ulcers
Respiratory problems
Weakened immune systems
Kidney and liver damage
Alteration of genetic material
Lung cancer
Death

The health hazards of exposure to chromium depend on its oxidation status. The metal form (chromium as present in this product) is of low toxicity. The hexavalent form is toxic. Adverse effects of the hexavalent form on the skin may include ulcerations, dermatitis, and allergic skin reactions. Inhalation of hexavalent chromium compounds can occur as a result of ulceration and perforation of the mucous membrane of the nasal septum, pharyngeal and laryngeal irritation, bronchitis, bronchospasm, and edema. Respiratory symptoms may include coughing and wheezing, shortness of breath, and nasal itch.

What is Graphite? Properties, Application And Different Types of Graphite.

2020-08-29T10:33:00.003+05:30

What is Graphite?

Carbon Graphite

The term graphite is derived from the Greek word “graphein,” which means to write. The material is typically grayish-black in color and has a radiant black sheen. Graphite is a naturally-occurring form of crystalline carbon. It is a basic mineral that is found in metamorphic and igneous rocks. Graphite is a mineral of extremes. It is very soft, cracks with very mild pressure, and has a very low specific gravity. Graphite is a different material because it exhibits the properties of both a metal and a non-metal. These fabulous properties give it a wide range of uses in metallurgy and manufacturing.

This uncommon combination of properties is due to graphite’s crystalline structure. The carbon atoms are set hexagonally in a planar condensed ring system. The layers are stacked parallel to each other. The atoms within the rings are bonded covalently, while the layers are loosely linked together by van der Waals forces. Graphite has a high degree of anisotropy, which is caused by two types of bonding acting in different crystallographic directions.

For example, graphite’s ability to develop a solid film lubricant is the outcome of these two contrasting chemical bonds. As weak Van der Waals forces control the bonding between each layer, they can slide against one another, making graphite an ideal lubricant.

Although graphite is adjustable, it is not elastic and has high electrical and thermal conductivity. It is also chemically inert and highly refractory. Since graphite displays low adsorption of X-rays and neutrons, it is very valuable in nuclear applications.

Graphite was first synthesized accidentally by Edward G. Acheson while he was doing high-temperature experiments on Carborundum. They found that about 4,150 ° C (7,500 ° F) silicon is vaporized in the carborundum, leaving carbon behind in graphical form. Acheson was granted a patent for graphite manufacturing in 1896, and commercial production began in 1897. Since 1918, petroleum coke, the small and incomplete graphite surrounded by organic compounds, has been a major raw material in the production of 99 to 99.5 percent pure graphite.

Physical Properties of Graphite:

Color	Steel gray to black
Chemical Classification	Native element
Streak	Black
Luster	Metallic, sometimes earthy
Diaphaneity	Opaque
Cleavage	Perfect in one direction
Mohs Hardness	1 to 2
Specific Gravity	2.1 to 2.3
Diagnostic Properties	Color, streak, slippery feel, specific gravity
Chemical Composition	C
Crystal System	Hexagonal

Applications of Graphite:

Amorphous graphite is used in:

Metallurgy
Coatings
Lubricants
Refractories
Paint production
Pencil production

Areas, where crystalline graphitecan be used, include:

Lubricants
Powder metallurgy
Grinding wheels
Batteries

Flake graphite is generally used in refractory applications, secondary steelmaking. Apart from this, it may also be used in pencils, powder metallurgy, coatings, and lubricants. Many sources of natural graphite is also used in the construction of graphite foil.

Areas, where synthetic graphiteis used, include:

Aerospace applications
Carbon brushes
Graphite electrodes use for electric arc furnaces for metallurgical processing
Moderator rods in nuclear power plants
Batteries

The high level of porosity of synthetic graphite makes it unsuitable in refractory applications.

Classifications of Graphite ( Different Types of Graphite)

Graphite can be divided into two main types—natural and synthetic.

Natural Graphite

Natural graphite is a mineral formed of graphitic carbon. It varies considerably in crystallinity. Most of the commercial (natural) graphite’s are mined and typically contain other minerals. After graphite is mined, it usually requires a considerable amount of mineral processing like froth flotation to concentrate the graphite.

Natural graphite is an excellent conductor of heat and electricity, stable over a broad range of temperatures, and highly refractory material with a high melting point of 3650 °C.

There are three types of natural graphite:

Crystalline Graphite
Amorphous
Flake

Crystalline Graphite (vein, a lump or crystalline vein)

It is said that crystalline vein graphite came from crude oil deposits that have transformed into graphite through time, temperature, and pressure. Vein graphite fissures typically measure between 1 cm and 1 m in thickness and usually has a purity of more than 90%.

Only extracted from Sri Lanka
Carbon content of 90-99%
Scarcity and high cost restricts viability for most applications

Amorphous Graphite:

Amorphous graphite is the most limited graphitic among the natural graphites. However, the term “amorphous” is incorrect as the material is still crystalline. Amorphous graphite can be found in the beds of mesomorphic rocks in the form of coal, slate, or shale deposits as minute particles. The graphite content different from 25% to 85% according to the geological environment.

Most abundant form of graphite
Comparatively low carbon content of 70-80%
No visible crystallinity
Lowest purity
Not of proper quality for use in most applications

Flake Graphite

Flake graphite can be found in metamorphic rocks evenly spread through the body of the ore or in concentrated lens-shaped pockets. The range of carbon concentrations varies from 5% to 40%. Graphite flake can be found as a lamella or scaly form in specific metamorphic rocks such as limestone, gneisses, and schists.

Froth flotation is used to extract flake graphite. “Floated” graphite has 80%–90% graphite content. More than 98% of the layer is made using graphite chemical beneficiation processes. Flake graphite can be found in many places worldwide.

Less common form of graphite
Carbon range of 85-98%.
Priced ~4X higher than amorphous graphite
Used in many traditional applications
Desirable for emerging technology graphite applications (e.g. Li-ion battery anode material)
Crystalline small flakes of graphite (or flake graphite) occur as isolated, flat, plate-like particles with hexagonal edges if unbroken.
When broken edge may be irregular or angular;

The lump graphite (or vein graphite) occurs in the fissure veins or crevices and appears as massive plateaus of fibrous or aquatic crystalline grosses, and is hydrothermal in origin.

Highly ordered pyrolytic graphiteintroduces to graphite with an angular spread among the graphite sheets of less than 1°.

Synthetic Graphite

Synthetic graphite can be generated from coke and pitch. Although this graphite is not as crystalline as natural graphite, it is possible to have higher purity. There are basically two types of synthetic graphite. One is electro graphite, pure carbon produced from coal tar pitch, and calcined petroleum coke in an electric furnace. The second is synthetic graphite, created by heating calcined petroleum pitch to 2800 °C.

Basically, synthetic graphite has higher electrical resistance and porosity, and lower density. Its enhanced porosity makes it unsuitable for refractory applications.

Synthetic graphite contains mainly graphitic carbon that has been attained by graphitization, heat treatment of non-graphitic carbon, or chemical vapor deposition from hydrocarbons at temperatures over 2100 K.

Different Industrial Use of Graphite

Use of graphite refractory materials;

On account of its high-temperature stability and chemical inertness, graphite is the perfect candidate for refractory material. It is used in the production of refractory bricks as well as “Mag-carbon” refractory bricks (Mg-C). In addition, graphite is used to produce crucibles, ladles, and molds for holding molten metals. Moreover, graphite is one of the most basic materials used in the production of functional refractories for the continuous casting of steel.

Here, graphite flake is mixed with alumina and zirconia, and then isostatically pressed to create components like stopper rods, subentry nozzles, and ladle shrouds used for regulating the flow of molten steel and also for safeguarding against oxidation. This type of material could also be used as protection for pyrometers.

In iron production, graphite blocks are used to produce a portion of the lining of the blast furnace. Their structural strength at high temperatures, thermal shock resistance, high thermal conductivity, low thermal expansion, and good chemical resistance is highly important in this application.

The electrodes used in many electrical metallurgical furnaces are mass-produced from graphite, for instance, the electric arc furnaces used for processing steel.

Graphite Electrodes:

Graphite can be generated from low-sulfur needle petroleum coke, which must be heated above 5,432 degrees Fahrenheit. Graphite is used in the production of electrodes for electric arc furnaces used in the steel-making industry. The execution of these electrodes depends on the quality and purity of the petroleum coke used. Graphite electrodes are highly demanded in the steel-making industry, because of their low coefficient of thermal expansion, which is related to the capacity of resisting high temperatures.

Use of graphite in the Chemical industry

In the chemical sector, graphite is employed in many high-temperature applications, like in the production of phosphorus and calcium carbide in arc furnaces. Graphite is used as an anode in specific aqueous electrolytic processes such as the production of halogen (chlorine and fluorine).

Use of graphite in the Nuclear industry

Large amounts of high-purity electrographite are used for producing moderator rods and reflector components in nuclear reactors. The suitability of electrograms comes from the low absorption of neutrons, high thermal conductivity, and high power at high temperatures.

Use of graphite in Electrical applications

Graphite is mainly used as an electric material in the manufacture of carbon brushes in electric motors. Here, the component’s service life and performance largely depend on grade and structure.

Use of graphite in Mechanical applications

Graphite is widely used as an engineering material across a variety of applications such as piston rings, thrust bearings, journal bearings, and vanes. Carbon-based seals are used in the fuel pumps and shafts of several aircraft jet engines.

In this article, you learn about what is Graphite, Properties, Application, and types of Graphite. If you have any queries regarding this article ask by comment below. If you like this article, don’t forget to share it on social networks. Thanks for giving your valuable time to this article.

What is Cast Iron? There Types, Composition, Properties, Application, Advantages and Disadvantages

2020-08-26T12:17:00.010+05:30

What is Cast Iron?

Cast iron is an iron alloy that contains more than 2% carbon. Although it can contain any percentage of carbon between 2% and 6.67%, in practice it is only between 2% to 4%. And also have varying amounts of silicon and manganese and traces of impurities such as sulfur and phosphorus. It is made by reducing iron ore in the blast furnace. Liquid iron is cast or cast into raw piglets in the form of pigs and hardened, and the pigs are then re-molten in cupola furnaces with scraps and alloying elements and to manufacture a wide variety of products. Is converted into molds.

Cast iron is a brittle and less ductile material with high corrosive strength. Due to its high compressive strength, it is used to make the base or body of most machines. Cast iron also has a low melting point of about 1200 degrees centigrade which makes it suitable for casting. It is named cast iron due to its casting properties. It has low manufacturing costs and has excellent machining properties.

What will you know after reading this article?

What is the Difference Between Steel and Cast Iron?
CastIron Composition and Properties.
Types of Cast Iron.
Use of Cast Iron (Application of Cast Iron).
Advantages and Disadvantages of Cast Iron.

What is the Difference Between Steel and Cast Iron?

There is a fundamental difference between cast iron and steel. Cast Iron contains more than 2% carbon and Steel contains less than 1% carbon.

Cast iron is cheaper than most steels. Also, the cast iron melting temperature is lower than that of steel, but it has high compressive strength, high hardness, and high wear resistance. Therefore, the important difference between steel and cast iron is that steel is ductile and malleable, whereas cast iron is hardened and has high compressive strength.

As another important difference between steel and cast iron, we can say that carbon in steel is in the form of iron carbide while cast iron has carbon as graphite or iron carbide or both. In addition, cast iron has excellent fluidity, with no steel.

Cast Iron Composition and Properties:

Cast iron also contains a small number of impurities such as silicon, sulfur, manganese and phosphorus, copper, nickel, chromium, which affect its properties on a small or large scale. The effect of these properties as follows.

Silicon:In cast iron, silicon particles have up to 4 percent presence. It promotes graphite formation which makes it soft and easily machinable and Increases hardenability and electrical resistivity.

Sulfur: It is present up to 0.1 present. It makes cast iron hard and brittle.

Manganese:It promotes carbide formation of cast iron which makes it elite, hard and increases resistance to wear and abrasions. It is present up to 0.75 percent.

Chromium:It also promotes carbide formation which Increases hardenability, wear resistance, corrosion, and oxidation resistance.

Nickle:Increases tensile strength.

Tungsten:It increases hot hardness and hot strength.

Molybdenum:Increases hardenability.

Vanadium:Increases hardenability and hot hardness.

Aluminum:Works as deoxidizer in steel.

Titanium:Works as deoxidizer in steel.

Niobium:It reduces hardenability and increases ductility, which results in increased impact strength.

Cobalt:It reduces hardenability and resists softening at elevated temperatures.

Types of Cast Iron

According to carbon percentage, cooling conditions, alloying elements, heat treatment, etc. cast iron may be divided into the following types.

Gray Cast Iron:

Cast iron which contains carbon in free form, known as Gray cast iron. It is also known as commercial cast iron due to mostly used for commercial purposes. It contains 3 to 3.5 percentile carbon and rests iron. This cast iron has low tensile strength, high compressive strength, and no ductility. It has excellent machining property. This metal is designate by FG followed by the digit show maximum tensile stress.

White Cast Iron:

Cast iron in which carbon is present in a combined form or in carbide form known as white cast iron. White color is due to carbide formation. It contains up to 2.3 percent of carbon. It is hard and not suitable for machining. This iron has high tensile strength and low compressive strength.

Malleable Cast Iron:

This cast iron is obtained from white cast iron by the heat treatment process. It is mostly obtained by annealing of white cast iron. It has improved strength and ductility like steel but can be easily cast. It is often used for small tensile, with good tensile strength and the ability to flex without breaking (ductility). Uses include electrical fittings, hand tools, pipe fittings, washers, brackets, fence fittings, etc.

Nodular Cast Iron:

It is also known as ductile or high strength cast iron. It has a high strength. It is obtained from Gray cast iron by adding a small amount of magnesium to the molten stage. It is designated by SG followed by the numbers which indicate tensile strength and percentage elongation.

Mottled Cast Iron:

Cast iron which has an equal amount of free carbon and carbide known as mottled cast iron. It has intermediate property and color of Gray cast iron and white cast iron.

Chilled Cast Iron:

If the white cast iron quickly cooled from the molten stage, the iron produced is known as chilled cast iron.

Alloy Cast Iron:

Alloy cast iron produced by adding some alloying elements in cast iron like nickel, chromium, copper, etc. It has increase properties according to the alloying element. This cast iron is produced to get the desire properties of cast iron.

Use of Cast Iron (Application of Cast Iron):

Grey cast iron: Engine cylinder blocks, flywheels, gearbox cases, machine-tool bases.
White cast iron: Bearing surfaces.
Ductile cast iron: Gears, camshafts, crankshafts, piston ring.
It is used in making pipes, to carry suitable fluids
It is used in making different machines
It is used in making automotive parts
It is used in making pots pans and utensils
It is used in making anchors for ships.

Advantages and Disadvantages of Cast Iron.

Advantages of cast iron

It has Good casting properties
It is available in large quantities, hence produced on a mass scale. Tools required for the casting process are relatively cheap and inexpensive. This results in a low cost of its products.
It can be given any complex shape and size without using costly machining operations
It has three to five times higher compression strength than steel.
It has Good machinability (gray cast iron)
It has excellent anti-vibration (or damping) properties so it is used to make machine frames.
It has good Sensibility
It has excellent resistance to wear
It has constant mechanical properties between 20 and 350 ° C.
It has very low notch sensitivity
It has Low-stress concentration
It bears Low cost
It has Durability
It has Resistance to deformation

Disadvantages of cast iron

It is Prone to rust
It has a poor tensile strength
Its parts are section sensitive; this is due to the slow cooling of thick sections.
The failure of its parts is sudden and in total, it does not reflect the yield point.
It has poor impact resistance
Compared to steel it has poor machinability
It has High weight to strength ratio
It has High brittleness
It is Nonmachinable (white cast iron).

In this article, you learn about what is cast iron and types of cast iron. If you have any queries regarding this article ask by comment below. If you like this article, don’t forget to share it on social networks. Thanks for giving your valuable time for this article.

What is IC Engine? There classification, Application And working process.

2020-08-25T13:30:00.015+05:30

What is IC Engine?

IC Engine

An IC engine is one type of heat engine in which the combustion of an air mixture with a fuel in a combustion chamber is an integral part of a working fluid flow circuit. In an internal combustion engine, the expansion of high-pressure and high-temperature gases produced by combustion applies direct force to some component of the engine. The force is applied typically to pistons, turbine blades, rotors, or a nozzle. This force moves the component at a distance, converting chemical energy into useful work.

IC Engines are the most common form of heat engines, as they are used in vehicles, boats, ships, airplanes, and trains. They are named as such because fuel is ignited to work inside the engine. The same fuel and air mixture are emitted as exhaust.

What will you know after reading this article?

When Does Invented the IC Engine?
How Dose IC Engine Work?
What is the Applications of IC Engine?
Classification of IC Engine.

When Does Invented the IC Engine?

The first, commercially the successful internal combustion engine was created by Étienne Lenoir around 1860 and the first modern internal combustion engine was created in 1876 by Nicolaus Otto.

How Does IC Engine Work?

IC Engine Animation

Combustion, also known as burning, is the basic chemical process of releasing energy from an air and fuel mixture. In an IC Engine, fuel ignition and combustion take place within the engine itself. The engine then partially converts energy from combustion into work. The IC engine consists of a fixed cylinder and a moving piston. Extended combustion gases push the pistons, which in turn rotate the crankshaft. Ultimately, through a system of gears in the powertrain, this motion drives the vehicle’s wheels.

There are currently two types of internal combustion engines in production: spark-ignition gasoline engines and compression ignition diesel engines. Most of these are 4-stroke cycle engines, meaning four piston strokes are needed to complete a cycle. The cycle involves four different processes: intake, compression, combustion and power stroke, and exhaust.

Spark ignition gasoline and compression ignition diesel engines differ in how they supply and ignite fuel. In a spark-ignition engine, fuel is mixed with air and then incorporated into the cylinder during the intake process. After the piston compresses the air-fuel mixture, the spark ignites it, causing combustion. The expansion of the combustion gas pushes the piston during the power stroke. In a diesel engine, only air is incorporated into the engine and then compressed. Diesel engines then spray fuel into hot compressed air at a suitable, measured rate, which ignites it.

What is the Application of IC Engine?

IC engine has many applications like,

Road Vehicle (e.g. Scooter, motorcycle, buses, etc.)
Aircraft
Motorboat
Small Machines, Such as Lawnmowers, chainsaws, and a portable engine generator.

Classification of IC Engine:

IC engines can be classified on the basis of fuel used, thermodynamic cycle, type of ignition, type of cooling system, cylinder the arrangement, method of charging, etc. Now we study it in detail.

According to Cycle of Operation:

We know IC engines convert chemical energy into mechanical energy in cyclic operation. There are many thermodynamic cycles e.g. Carnot cycle, Otto Cycle, Diesel Cycle, Rankine cycle, etc. IC engines work on three cycles Otto cycle and Diesel cycle and Dual cycle. So according to it, IC engine can be classified into the following types.

Otto Cycle Engine:

It is also known as a spark-ignition engine or constant volume heat addition engine, Petrol engine, etc. In this cycle heat addition (fuel burn) and rejection (exhaust) takes place at constant volume and expansion and compression take place at isentropic. These engines give low power at high speed.

Diesel Cycle Engine:

This is known as a compression-ignition engine, diesel engine, constant pressure engine, etc. In this cycle heat addition (fuel burn) takes place at constant pressure and heat rejection takes place at constant volume. This engine gives high power at low speed.

Duel Cycle Engine:

The dual cycle is a combination of the Otto cycle and the diesel cycle. In this engine, heat addition takes place both at constant volume and constant pressure in some ratio.

Some engines work on Stirling cycle and Ericsson cycle but these are not used commercially.

According to Type of Fuel Used:

Most of us know about these engines. These are petrol engines and diesel engines. Nowadays gaseous fuel like LPG, CNG, hydrogen, etc. is also used in IC engines. These engines are called non-traditional engines.

According to the Method of Charging:

The charging means how the admission of the fuel-air mixture takes place. This can be classified as follow.

Natural aspirated engine:

In this engine, admission of the air-fuel mixture (SI Engine) or air alone (CI engine) takes place due to pressure difference inside the cylinder and atmospheric pressure.

Supercharged Engines:

In this engine, a separate compressor is used to the admission of charge inside the cylinder. This compressor is run using engine power (connected with the crankshaft with belt drive).

Turbocharged Engine:

This engine uses a turbine that draws air into the cylinder and runs by using exhaust gas power. It is also like supercharge but the compressor is run by a turbine which is rotated by exhaust gases.

According to Ignition:

In IC engine ignition of charge can take place in two ways. In the first one, a separate spark plug or any other device used to ignite the fuel (Spark Ignition Engine) and the other one is fuel ignite due to heat generated during compression or fuel (Compression Ignition Engine). So according to these methods, two engines are available spark-ignition engine or SI engine (Petrol Engine) and compression ignition engine or CI engine (Diesel Engine).

According to a type of Ignition System:

In petrol engines, we used a spark plug to ignite the fuel. This spark at the spark plug, produce by an ignition system. According to the ignition system, two types of engines are there. The first one is the battery ignition engine (use a battery to generate spark) and another one is a magneto ignition engine (use a small generator to generate spark).

According to Design of Engine:

Reciprocating Engine:

In this type of engine, a piston is used which moves in reciprocating motion by using pressure force generated by the burning of fuel. The crankshaft converts this reciprocating motion into rotary motion. Most of the automobile engines are reciprocating type.

Rotary Engine:

In a rotary engine, a rotor is used. The pressure force generated by the burning of fuel exerted on this rotor, which further rotates the wheel. The Wankel engine is one type of rotary engine. These engines are currently not used in automobile engines.

According to cooling:

Two types of cooling used in IC engines, air cooling, and water cooling. So the engines are air-cooled engine or water-cooled engine. Both these cooling systems have their own advantages, which we will discuss later. Engine oil is also serving as a cooling medium.

According to stroke of engine:

We know that the stroke is the maximum distance a piston can travel inside a cylinder or between TDC to BDC. If an engine moves from TDC to BDC, it is called one stroke. If it returns to BDC it is called two strokes. A crankshaft makes one rotation in two strokes. According to it, three types of engines have invented.

Two-stroke Engine:

In this engine, crankshaft makes one rotation in one power stroke. This engine gives more power compare to others. It is used in shooters, ships, generators, etc.

Four-stroke engines:

This engine gives two crankshaft rotation in one power stroke. They give low power but high efficiency. It is used in cars, trucks, bikes, etc.

Six stroke engines:

These engines are in the development process. As the name implies, it will give three crankshafts rotation in one power stroke.

According to an arrangement of engine:

These engines can be better understood by diagram compare to words.r.

What is piston ring ? there types, function and working process.

2020-08-24T18:32:00.017+05:30

What is Piston Ring?

Piston Ring

An internal combustion engine is a heat engine in which combustion (burning of fuel) takes place inside the cylinder which generates a high temperature and pressure force which further used for useful work. This function of the IC engine achieved by various parts working together. These parts are tied together and the combination of all these parts is known as an engine. The piston ring is one of the essential auto parts. Today I am going to tell you about this ring, its function, its types any many other facts related to it. So, let’s start.

Pistons are equipped with some metal rings which perform many functions. These rings are known as piston rings.

What will you know after reading this article?

Material which is used to make a piston ring.
What is the function of the Piston Ring?
What are the 3 types of piston rings?
How Do Piston Rings work?

Material which is used to make a piston ring.

One of the most prominent materials used in making piston rings is cast iron. This is because it contains graphite in the lamellar form which itself acts as a lubricant assisting the sliding motion between the rings and the liner. Alloys and coatings are done on the piston rings, and it will vary as per the type of the ring as the functionality of these rings are different from each other. The most common forms of alloy cast iron are chromium, molybdenum, vanadium, titanium, nickel, and copper.

The piston ring material is kept harder than the cylinder liner to provide maximum life.

What is the function of the Piston Ring?

Gas Seal Function

Gas seal Function

This means that the combustion chamber should be as gas-tight as possible, so that the pressure generated by the burning combustion gases quickly transfers the piston to the cylinder, causing the crankshaft to turn, thereby providing power. Not only important for the combustion/expansion stroke, but gas-tightness is also very important for the intake, compression, and exhaust strokes as well. This general function can only be called "gas sealing".

Heat transfer Function

Heat transfer function

Piston rings serve to move the hot piston away from the engine's quiet cylinder wall/block. Heat energy moves from the piston groove to the piston ring and then into the cylinder wall, where it will eventually be transferred to the engine coolant. This heat transfer function is very important to maintain acceptable temperature and stability in pistons and piston rings so that the sealing capacity is not impaired.

Oil control function

Oil Control function

Piston rings require some oil for lubrication; Although, it is desirable to keep this amount to a minimum. The rings act in a scraping manner, removing excess oil from the combustion chamber. In this way, oil consumption is at acceptable levels and harmful emissions are reduced. older than the cylinder liner to provide maximum life.

What are the 3 types of piston rings?

Piston rings commonly used on small engines include the compression ring, wiper ring, and oil ring.

Compression Ring

The compression ring is the top or nearest ring for the combustion of gases and is exposed to the highest amount of chemical corrosion and the highest operating temperature. However, this may vary according to the design of the engine. The compression ring assigns 70% of the combustion chamber heat from the piston to the cylinder wall. Most engines use either taper-face or barrel-face-compression rings.

Taper faced compression ring

A Taper faced compression Ring which is a piston ring with a taper angle of about 1 ° on the moving surface. This cone provides light wipes to prevent any excess oil from reaching the combustion chamber.

Barrel faced compression ring

A barrel faced compression ring is a piston ring with a curved surface rotating to provide continuous lubrication of the piston ring and cylinder wall. It also provides a spike effect to optimize oil distribution during the entire stroke of the piston. In addition, the curved moving surface reduced the possibility of an oil film breaking due to excess pressure or excessive piston tilt at the ring edge during operation.

Wiper Ring

The wiper ring, sometimes called the scraper ring, Napier ring, or back-up compression ring is the next ring apart from the cylinder head on the piston. The wiper ring provides a consistent thickness of the oil film to lubricate the running surface of the compression ring. Most wiper rings have a taper angle face that is positioned downward to provide a wipe action as the piston moves toward the crankshaft.

The taper angle provides contact that routes excess oil to the oil ring on the cylinder wall to return to the oil reservoir. A wiper ring is closest to the incorrectly tapped angle to the compression ring, resulting in excessive oil consumption. This is caused by the wiper ring wiping off excess oil towards the combustion chamber.

Oil Ring

Oil Ring Cross Section

An oil ring consists of two thin rails or a running surface. The cut holes or slots in the radial center of the ring allow excess oil to flow back into the reservoir. Incorporating all these features, oil rings are usually one piece. Some oil rings use a spring expander to apply additional radial pressure to the piston ring. This increases the pressure applied to the unit (the amount of force and the size of the movable surface) on the cylinder wall.

The oil ring has the highest inherent pressure out of the three rings on the piston. Tree-piece oil ring consisting of two rails and an extender. The oil rings are positioned on each side of the expander. The expander usually has multiple slots or windows to return oil to the piston ring groove.

The oil ring uses the built-in piston ring pressure, extensor pressure, and the high unit pressure provided by the small running surface of the thin rail.

How Do Piston Rings work?

As explained, there are different types of rings provided in a piston at various levels, which perform different tasks.

The topmost groove of the piston consists of a compression ring whose main function is to seal any kind of leakage inside the combustion chamber during the combustion process. When the air-fuel mixture is ignited, pressure from the combustion gases is applied to the piston head, forcing the piston towards the crankshaft.

Pressurized gases pass through the gap between the cylinder wall and the piston and into the groove of the piston ring. During the combustion process, the force of high-pressure gases presses the piston ring against the cylinder liner wall which helps it to form an effective sealing. This pressure pushing the piston ring is proportional to the combustion gas pressure.

The next set of rings in the piston which are placed below the compression ring and above the oil rings are called wiper rings.

They have a tapered face construction and it is used to further seal the combustion chamber. As the name suggests, they assist in wiping the liner wall clean of any excess oil and impurities. If any of the combustion gases were able to pass by the compression ring, these gases will be blocked by the wiper ring in a good condition.

The last set of rings are oil rings which are located at the bottom grooves of the piston closest to the crankcase. The main function of the oil ring is to scrape any excess oil from the walls of the cylinder liner when the piston is in motion. The majority of the wiped oil is directed into the crankcase back to the oil sump. These oil rings come with spring fitted at the back in a 4-stroke engine to provide an additional push for wiping the liner.