Difference between forging and casting

What is casting?

Casting is a process in which metal is heated until the molten stage and poured or forced this metal into a mould or cavity such that the metal solidifies and takes the shape of the mould. 

Types of casting are gravity casting (including sand casting and die casting) and pressure casting (including low-pressure casting and high-pressure casting).

What is forging?

Forging is a process of reforming a metal shape by applying pressure with or without heat. 

Types of forging are impression die forging, cold forging, open die forging and seamless rolled ring forging. 

Now, let us have a deep insight into the comparison between them and check it out the difference between them too. 

Difference : 

• In casting metal is heated until it converts into a molten stage wherein forging metal is heated below re-crystallization temperature. 
• A product produced by the casting process has low fatigue strength and by forging process has high fatigue strength. 
• Imperfection or defects does not improve in casting and defects are refined in the forging process.
• The casting process is less reliable or has low strength while forging process is highly reliable.
• Casting is costly sometimes and has a high lead time where forging has low lead time and cheap as compared to casting.
• The product produced by the casting process has low tensile strength while forging product has high tensile strength.
• Casting process required a secondary finishing operation while forging process not required. 
• The product produced by the casting process has high compressive strength as compare to forging. 
• The casting process involves pouring of molten metal into a mould for cooling while in forging can be done to cold, warm and hot metal depending on the requirement of the final product.
• The product produced by casting has a low tensile strength than the forging. 
• Forging is costly sometimes and has high lead time whereas forging has low lead time and cheap. 
• Casting process response to heat treatment requires close control due to the probability of alloy segregation while in forging a response to heat treatment is better.

Difference between MIG and TIG welding

The difference between them is MIG welding uses a continuously feeding wire and the TIG welding use long welding rods and slowly feed them into the weld puddle. Both welding processes uses an electric arc to make the weld. Let us have a deep insight into the comparison and difference between MIG and TIG welding process. 

Difference : 

• The MIG welding process is done with metal inert gas whereas the TIG welding process is done with tungsten inert gas.
• In MIG welding metal rod is used as electrode and workpiece used as another electrode while in TIG welding tungsten rod is used as an electrode.
• MIG welding is gas shielded metal arc welding and TIG welding is gas shielded tungsten arc welding. 
• In MIG, the welding area is flooded with a gas that does not combine with the metal whereas TIG gas is used to protect the welded area from the atmosphere. 
• TIG welding is a more versatile process than MIG welding because able to change filler material quickly.
• MIG welding torch is bulkier compared to TIG welding torch.
• TIG welding is preferred where a high quality of weld (radiography) is essential.  
• MIG electrode is consumables but in the case of TIG is tungsten which is not consumables. 
• MIG welding is a very simple and easy process to learn compared to TIG welding. 
• MIG welding process is comparatively faster than TIG welding. 
• Filler metal is compulsorily used in MIG welding while may or may not be used in TIG welding. 
• MIG welding use DC for arc and TIG welding is used both DC and AC. 
• MIG welding can weld up to 40 mm thick metal sheet whereas thickness is limited about 5 mm in case of TIG welding. 

Difference between horsepower and torque

What is Horsepower?

A horsepower is a unit of measurement design to quantify the work an engine is doing. 

What is torque?

Torque is a twisting force that transmitting power from engine transmission to differential.  

Let us have a deep insight into the difference between torque and horsepower. 

Difference : 

• Torque is the amount of force that can be applied whereas horsepower is a measurement of that torque overtime gave RPM.
• Horsepower and torque measure different things. Horsepower is a measurement of the power of the rate at which work is done and torque measures the rotating force around an axis.
• The horsepower rating would determine the top speed of the car and, on the other hand, torque would determine how a car would accelerate.

Difference between pump and compressor

The main difference is pump are used to transfer liquid from low-level head to high-level head while the compressor is used for gases to transform from low to much high pressure. Mechanically water is in-compressible so it can't be used in compressors. Let us have a deep insight into the difference between pump and compressor. 

Difference :

• The pump is a device which is used to increase the pressure of incompressible fluids like liquid fluids whereas the compressor is a device which is used to increase the pressure of compressible fluids like gaseous fluids.
• Pump has got more to do with the head at increased pressure but no significant change in temperature while the compressor has got more to do with the increased pressure and increased temperature.
• A pump used to move the fluid at any height from one location to another where the compressor increases the fuel pressure or potential energy.
• Pump increase pressure of the fluid by moving it at any height where the compressor increases the pressure of the fluid by compressing it.
• There is no change of volume from inlet to outlet in the pump and in compressor change in volume from inlet to outlet.
• A compressor has storage capacity while no storage capacity in a pump. 
• The pump is relatively cheaper as compared to the more expensive compressor. 

Basically, with a pump, both input and output are open to equal atmosphere, but with a compressor, we output into a regulated, fixed-volume container for deliberate disequilibrium (pressure).

The most important misunderstanding people have is between flow and Pressure.

Difference between Manufacturing and Production

Manufacturing and production are often used as the same terms but there is a big difference between them. Let us have a deep insight into the comparison and difference between both of them.

What is manufacturing?

Manufacturing is the process of converting raw material into a tangible, ready-to-sell finished product with the use of many processes. The manufactured product can be directly sold to the end customer. Almost all the processes add value to the material but also consume some material for adding value. Mostly men, machine and material are required as a resource and a lot of planning goes into this. 

What is production?

Production is a process to convert any type of inputs to output, tangible or intangible. Mainly Production is the creation of utility includes both goods and services. 


Difference : 

• Manufacturing is used in the industries with production, whereas manufacturing refers to anything produced within or outside the industries.
• All sorts of manufacturing are related to production but not all production is manufacturing.
• When the raw material is used as input to produce goods using machinery whereas the process of transforming resources into finished products is known as production.
• Men-machine setup should be there for the manufacturing of goods, which is not in the case of production, the only man is sufficient for producing output.
• Manufacturing produces products suitable for use and production produces products such as artworks, paintings etc.
• Tangible products can be produced or manufactured but intangible products can just be produced.
• Manufacturing can be entirely by machines while production has done by individual employee too without the use of machines.
• In manufacturing, the company makes the final product after processed on the raw material from outside wherein this is not necessary for production in which the company processes the raw material to make a final product.  
• Men and machine both are required in manufacturing where the only man can produce output.
• The use of machinery is a must in manufacturing, whereas production can be done with or without machinery.

Terminology of Spur Gear

Pinion : A pinion is a smaller of the two mating gears.

Gear : A gear is the larger of the two mating gears.

Velocity Ratio : Ratio of angular velocity of the driving gear to the angular velocity of the driven gear. It is also called speed ratio.

Transmission Ratio : Ratio of the angular speed of the first driving gear to the angular speed of the last driven gear in a gear train.

Pitch Surface : The pitch surface of the gears are imaginary planes, cylinders or cones that roll together without slipping.

Pitch Circle : The pitch circle is the curve of intersection of the pitch surface of revolution and the plane of rotation. It is and imaginary circle that rolls without slipping with the pitch circle of a mating gear.

Pitch Circle Diameter : The pitch circle diameter is the diameter of the pitch circle. The pitch circle diameter is denoted by d.

Pitch Point : It is a point on the line of centres of two gears at which two pitch circles of mating gears are tangent to each other.

Top Land : It is the surface of the top of the gear tooth.

Bottom Land : It is surface of the gear between the flanks of adjacent teeth.

Involute : An involute is a curve traced by a point on a line as the line rols without slipping on a circle.

Base Circle : The base circle is and imaginary circle from which the involute curve of the tooth profile is generated. The base circle of two mating gears are tangent to the pressure line.

Addendum Circle : The addendum circle is an imaginary circle that borders the tops of gear teeth in the cross section.

Addendum : The addendum is radial distance between pitch and addendum circle. It indicates the height of the tooth above the pitch circle.

Dedendum Circle : The dedendum circle is an imaginary circle that borders the bottom of spaces between teeth in the cross section. It is also called root circle.

Dedendum : The dedendum is the radial distance between pitch and the dedendum circles. It indicates the depth of the tooth below the pitch circle.

Clearance : The clearance is the amount by which the dedendum of a given gear exceeds the addendum of its mating tooth.

Face of tooth : The surface of gear tooth between the pitch cylinder and the addendum cylinder is called the face of tooth.

Flank of tooth : The surface of the gear tooth between the pitch cylinder and the root cylinder is called flank of tooth.

Face width : Face width is the width of the tooth measured parallel to the axis.

Fillet Radius : The radius that connects the root circle to the profile of the tooth is called fillet radius.

Tooth Space : The width of space between two adjacent teeth measured along the pitch circle is called tooth space.

Working Depth : The working depth is the depth of engagement of two gear teeth that is sum of their addendums.

Whole Depth : The whole depth is total depth of the tooth space that is sum of the addendum and dedendum.

Whole depth = Working depth + clearance

 

Centre Distance : The centre distance is the distance between centres of pitch circles of mating gears.

Pressure angle : The pressure angle is the angle which the line of action makes with the common tangent to the pitch circles. It is also called angle of obliquity. It denoted by α.

Difference between BE and B.Tech

There is no difference between the B.E and B.Tech in terms of value and scope. Now let’s dig the question little deep.

The B.Tech course is a little more practical than the more theoretical BE course.

B.E is knowledge-oriented whereas B.Tech is skill-oriented. 

Bachelor of Engineering is a science, dealing more with theoretical concepts & principles.

Bachelor of Technology deals more with the application of these theories for practical purposes. But, both B.E. & B.Tech courses offered by various engineering colleges or institutes.

Difference between shaft and axle

The shaft is a rotating element, circular in cross-section that supports transmission elements like gears, pulley, and transmits the power while the axel is a supporting rotating element like wheels, and is fitted to the housing by means of bearing. The axle may be rotating as well as stationery too. Let us have a deep insight into the comparison and difference between shaft and axle. 

Main difference :

The main difference is that the shaft is used to transfer the power from one mechanical member to the other while the axle is used for just support the load. 

Difference : 

• The shaft is a live member while the axle is a dead one.
• Axle subjected to only bending moments whereas the shaft subjected to bending moment and twisting moment and sometimes the axial loads. 
• Shafts are the used to transfer torque and bending moment to another member by means of rotation while the axle is stationary used to transfer bending moment.
• The shaft can take a load on shaft circumference while axle can take the load at the centre or any of its circumference.
• The shaft is used for rotary motion while the axle is used for linear or angular motion.
• The shaft used to transmit power at a short distance while axle transmits power at long distance.
• The shaft can be meant for balancing or transferring torque while the axle is meant for balancing or transferring bending moment.
• Shaft and axle both of have different functions drive train in a vehicle. Shaft transfers power from the transmission to the rear differential gearbox while axle transfer power from the rear differential gearbox to the wheels.
• A shaft is a hollow steel tube of greater diameter than an axle shaft and with universal joints on each end while Axle is made by solid-steel rods with teeth cut into their ends.

Types of Bearing

Bearing is a mechanical element that permits relative motion between two parts, such as the shaft and the housing, with minimum friction. 
The function of the bearing are the following :

• The bearing ensures free rotation of the shaft or axle with minimum friction.
• The bearing supports the shaft or axle and holds it in the correct position.
• The bearing takes up the forces that act on the shaft or the axle and transmit them to the flame.

Bearing are classified in different ways :

Depending upon the direction of the force that acts on them :

1. Radial bearing
2. Thrust bearing

Radial bearing supports the load, which is perpendicular to the axis of the shaft.

Thrust bearing supports the load, which acts along the axis of the shaft.

Depending upon the types of friction :

• Sliding contact bearing

Types of sliding contact bearing :

• Hydrodynamic bearing 
• Hydrostatic bearing 

• Rolling contact bearing 

Types of rolling contact bearing :

• Deep groove ball bearing
• Cylindrical roller bearing
• Angular contact bearing
• Self-aligning bearing
• Taper roller bearing
• Thrust ball bearing

Sliding contact bearing is any bearing that works by sliding action, with or without lubricant. This group encompasses essentially all types other than rolling-element bearings.

Sliding contact bearing is also called plain bearing, journal bearing or sleeve bearing.
Lubrication is critical to the operation of plain bearings, so their application and function are also often referred to according to the type of lubrication prin­ciple used. Thus, terms such as hydro­dynamic, fluid-film, hydrostatic, boundary-lubricated, and self-lubricated are designa­tions for particular types of plain bearings.

Application of Sliding Contact Bearing :

• Crankshaft bearing in petrol and diesel engine
• Centrifugal pumps
• Large size electric motor
• Steam and gas turbine
• Rope conveyors

Rolling contact bearing is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two bearing rings called races. The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding.  

The principal types of roller bearings are cylindrical, needle, tapered, and spherical. In general, they have higher load capacities than ball bearings of the same size and are widely used in heavy-duty, moder­ate-speed applications. However, except for cylindrical bearings, they have lower speed capabilities than ball bearings. See the following figure for roller bearings. 

 

 
Application of Rolling contact bearing :

• Machine tool spindles
• Automobile front and real axles
• Gear boxes
• Small size electric motors
• Rope sheaves
• Crane hooks
• Hoisting drums

Advantages and disadvantages of anti lock braking system

ABS is a safety system estimated wheel slip and uses brake modulation to reduce braking power to regain rolling in the wheels. It is a method of pumping the brakes very quickly to allow the driver to maintain the ability to steer in a panic braking situation. It allows to maintain the contact between wheel and road and avoid skidding and wheel locking. It also improves the control of a vehicle and decreases the stopping distance on a dry and slippy surface. Let us have a deep insight into the pros and cons of ABS in this article. 

Advantages of ABS :

• With the use of ABS stops the car at a shorter distance than the conventional brakes.
• Prevents the wheels from locking up hence avoids uneven tyre wear.
• Increases control.
• Enables the possibility of a traction control system.
• Better braking performance under most conditions.
• ABS offers more safety
• Significantly reduced risk of skidding while braking.
• Makes better use of the brake pads and brake disc.
• ABS allows you to steer your car around objects if any as you still have grip on the wheels under intense braking. 

Disadvantages of ABS :

• Inconsistent stopping distances on various surfaces under variable conditions.
• Under generally poor road conditions, ABS braking increases stopping distance.
• Experienced drivers can often brake better manually than with ABS brakes.
• More expensive to repair and maintain.
• Increases the cost of the vehicle.
• Involves the use of an extra sensor and a controller which increases the complexity.
• On concrete roads, the ABS vehicle stopping distance might be needed more.           

Advantages of MPFI system

MPFI state as a multi-point fuel injection system. The main function of the MPFI system is to supply a proper ratio of gasoline and air to the cylinders. Let us have a deep insight into the advantages of this system in this article.

Advantages of the MPFI system :

• MPFI improved fuel consumption.
• Mileage will be improved.
• ECM technique is used to control the engine.
• Precise supply of air-fuel mixture.
• The engine response is also good in the condition of the throttle applied.
• The MPFI engines vibrate less and don’t require to be cranked twice or thrice in cold weather.
• It helps in uniform combustion of fuel inside the combustion chamber.
• The exact and uniform quantity of the air-fuel mixture is provided for each cylinder.
• Cleaner emissions.
• MPFI improves the functionality and durability of the engine components.
• The mileage of the vehicle is improved. 

Working priciple of MPFI

• The MPFI is an advanced version of the carburettor engine. MPFI full meaning is a multi-point fuel injection system.
• Even though the working of MPFI engine is somewhat similar to the engine used by carburettor each cylinder is treated individually. 
• A separate injector supplies the correct quantity of fuel to each of the engine cylinders by a fuel-rail according to the firing order or in a particular sequence. This system provides further precision by varying the fuel quantity and injection timing by governing each injector separately and thereby improving the performance and controlling the emissions.
• The return valve returns fuel in case the fuel is oversupplied. Also, the pressure regulator regulates the pressure of the intake of  fuel. Fuel filter contains small-sized membranes which filter and absorbs undesirable matters of size 30 to 40 microns.
• The fuel and air are mixed in the intake manifold and each manifold is controlled by an ECU(Electronic Control Unit). fuel pressure runs between 3 to 5 bars.

Working Principle of ABS

Working principle of ABS ( Anti-lock Braking system ) :  

ABS full form is anti-lock braking system. It is very useful safety system of automobile. Now we can check it out the working principle of ABS.

• When the brakes are applied fluid is forced from the master cylinder to the HCU inlet ports with the help of open solenoid valves that are contained in the HCU, then through the outlet ports of HCU to the each wheel.
• The rear part of the master cylinder feeds the front brakes and vice-versa.
• After the fluid in inserted in each wheel, the wheel starts locking-up.
• When the control module senses that wheel is going to lock up, it closes the normally open solenoid valves for that wheel.
• The anti-lock break control module then looks at anti-lock break sensor signal from the affected wheel.
• Once the affected wheel comes back up to the speed, then the control module returns the solenoid valve to there normal condition.