vidyaa vikas college of engineering and technology … · 2018-05-08 · vidyaa vikas college of...

VIDYAA VIKAS COLLEGE OF ENGINEERING AND TECHNOLOGYDEPARTMENT OF MECHANICAL ENGINEERINGMANUFACTURING TECHNOLOGY – I (ME -6302)

QUESTION BANK

UNIT -1METAL CASTING PROCESS

TWO MARKS WITH ANSWERS

1. What is meant by grain fineness number? (AU. Dec.2014)

It is defined as the ratio between the total products and total percentages of sand retained onpan in each sieve.

2. Mention few applications of centrifugal casting.( AU. Dec 2014)

Components, such as water pipes, gears, bush bearings, fly wheels, piston rings, brake drums,Gun barrels, can by made by centrifugal casting.

3. State any four types of pattern.( AU. May 2012)

1. Solid or Single piece pattern 2. Split Pattern

3. Loose piece pattern 4. Match Plate Pattern

5. Sweep Pattern 6. Skeleton Pattern

7. Segmental Pattern 8. Shell Pattern

4. State the application of sweep and skeleton pattern. (AU. May 2011)

Sweep Pattern: Sweep pattern can be used for preparing moulds of large sym metrical castings,particularly of circular cross section.

Skeleton pattern: When the size of the casting is very large but easy to shape and only a fewnumbers are to be made. It is not economical to make a large solid pattern of that size. In Such cases, apattern consisting of wooden frame and strips is made. This is called as skeleton pattern.

5. What allowances are generally considered while making patterns. (AU. May 2011)

Five allowances are made on the patterns:

1. Shrinking allowances,

2. Draft allowances,

3. Finishing or machining allowances

4. Shake allowances

5. Distortion allowances.

6. State any four properties of moulding sand. (AU. May 2010)

1. Strength

2. Permeability

3. Flow ability

4. Collapsibility

5. Cohensiveness

6. Adhesiveness

7. Define permeability of moulding sand. (AU. Dec.2011)

It is the property of sand which permits the steam and other gases to pass through the sandmould. This refers to the ability of the sand to exhaust gases. If the sand is too fine, the porosity will below.

8. What are the ingredients of moulding sand? (AU. Dec.2011)

The main ingredients of moulding sand are.

1. Silica sand,

2. Clay,

3. Moisture,

4. Additives.

9. What is the function of a core? (AU. Apr.2010)

Cores are the sand forms that are placed in the mould cavity to form the holes. recesses andother interior surfaces and sometimes the external surfaces as well of the casting. Core is made fromthe core sand.

10. Differentiate the terms mould and core. (AU. Dec.2011)

Mould: Mould is a container made from moulding sand usually holds the liquid metal.

Core: Core is used to form the internal cavities and holes in the casting.

11. What is meant by core print? (AU. Nov.2011,Nov 2012,Nov 2015)

A core print is the projection provided on the core. Core-print provides support to the core andkeeps it in proper position.

12. Mention the need for using carbon-dioxide in mould preparation. (AU. Apr.2011)

Carbon- dioxide is used in the CO2 mould preparation. The CO2 hardens the mould easily andgives more strength than sand moulding without more ramming.

13. Compare the advantages of metal moulds over sand (expandable) moulds. (AU. May 2013)

1. Excellent dimensional accuracy

2. Smooth cast surfaces (1-2.5 micrometres)

3. Thinner walls can be cast as compared to sands.

4. Reduces or eliminates secondary machining operations.

5. Rapid production rates.

14. Which type of furnaces are suitable for melting of ferrous material and why? (AU. May 2010)

Induction furnace, Arc furnace

1. Induction heating is a clean form of heating.

2. High rate of melting.

3. Alloyed steels can be melted without and loss of alloying elements.

15. Name the different melting furnaces employed for metal casting. (AU. Dec.2012)

1. Cupola furnace

2. Open hearth furnace

3. Crucible furnace

4. Pot furnace

5. Electric arc furnace

6. Induction furnace

16. What are the functions of flux in melting metals and alloys? (AU. May 2013)

Flux is a chemical agent, flowing agent, or purifying agent. Fluxes may have more than onefunction at a time. Fluxes when added to the contents of a smelting furnace or a cupola for the purpose

of purging the metal of chemical impurities such as Phosphorus, and of rendering stag more liquid at thesmelting, temperature.

17. List the various sand casting defects. (AU. Dec.2013)

1. Pouring metal defects include misruns, cold shuts, and inclusions.

2. Gas porosity and blowholes or blisters.

3. Shrinkage defects.

18. Differentiate shrinkage and porosity. (AU. Nov.2013)

Shrinkage: Reduction of overall size or piping of casting due to phase change is shrinkage.

Porosity: Gas porosity is the formation of bubbles within the casting after it has cooled.

19. What are the causes for the formation of blow holes in the sand casting? (AU. May 2012)

Blow holes are caused by

1. Excessive moisture

2. Low permeability

3. Fine grain sands

4. Insufficient vent holes and

5. Too hard ramming.

20. Define casting. (AU. May 2014)

Casting is the metallic component taken from the mould by melting and poured into the mouldcavity.

21. What is pattern? (AU. June 2012)

Pattern is the model of anything. It is used for forming an impression called in dump sand.

SIXTEEN MARKS QUESTIONS:

1. Explain various properties required for the moulding sand. (AU. Dec 2014)

(Refer page No.1.23 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

2. Explain the various steps involved in sand core manufacturing. (AU. May 2009,Dec 2014)

(Refer page No.1 .57, Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

3. Describe briefly with sketches the steps involved in making a sand mould to cast the component.

Sketch also the shape of the casting as soon as it is removed from the mould. (AU. May 2014)


4. With reference to metal casting, explain the following types of patterns, with suitable sketches ofexamples. (Dec.2011)(Nov2015)

1. Solid pattern 2. Split pattern

3. Loose piece pattern 4. Sweep pattern


5. What are the allowances given while making a pattern? Explain (AU. Apr2010,Dec.2010,Dec.2012

May 2013)


6. Discuss any four sand testing methods. (AU. June 2009,May 2010)

(Refer page No.1.33, Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

7. What is core? Describe the different types of cores used. (AU. Nov.2009)


8. Explain the CO2 process of core making. State its advantages and applications. (AU. Dec.2011,May2013)


9. With suitable sketches, explain the various steps of investment casting process. What are its

advantages? (AU. Dec.2010, Apr 2011, DEC 2011,May 2012,May 2013)


10. With a neat sketch explain the centrifugal casting methods. (AU. Apr.2011, May 2012,Nov 2013)


11. Write short notes on the following:

1. Ceramic mould 2. Centrifugal casting. (AU. May 2012)

(Refer page No.1.98 & 1.108 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

12. Explain shell moulding with sketches and also list the advantages over other casting methods.

(AU. Nov/Dec.2013,Nov 2015)


13. Describe with a neat sketch of hot chamber and cold chamber die casting machine. Give itsadvantages and limitations. (AU. May 2013,May 2014)


14. Compare the differential types of furnaces, methods of heating and main field of application. (AU.Apr.2011)


15. Explain with neat sketch casting defects and its remedies. (AU. Nov.2010, Apr.2010, Apr,2011 ,Apr2012, Apr2013,May 2014,Nov 2015)


16. What are the non-destructive tests used in casting inspection? Explain any one method. (AU.May2009)


17.Describe the constructional feature of cupola furnace. (AU.May 2009,Dec 2014,Nov 2015)


UNIT -2JOINING PROCESSES

TWO MARKS WITH ANSWERS1. What is meant by Nuggest in Electrical Resistance welding?(Dec.2014)

The point at which the molten metal is created between for short period of time due tomaximum heat generation is called nuggest.

2. What are functions of flux in welding electrode? (Dec 2014)A flux is used during welding to present oxidation and to remove impurities.

3. Differentiate fission welding from fusion welding. (Nov.2010)Fission welding: In atomic Hydrogen welding heat is generated by passing a stream of Hydrogen

through an electric are between two inclined electrodes. The high temperature of the are dissociatesmolecules of the H2 into atoms, a large quantity of heat being absorbed by the hydrogen duringdissociation. When the atoms leave the influence of theare they recombine, forming molecules ofhydrogen and liberating heat previously absorbed.

Fusion welding: In fusion welding the metal pieces are melted and joined.

4. What is meant by ‘ carburizing flame’ in gas welding? (Nov.2012)The flame with excess amount of acetylene is called carburizing flame. The oxygen and

acetylene ratio is 1:1.2.This flame consists of three zones:1. The sharply defined inner cone2. The bluish outer envelope and3. The intermediate whitish acetylene feather

5. What are the functions of flux in welding electrode? (Dec.2013, June 2012)1. It prevents the oxidation of the weld pool, by forming a protective gaseous shield.2. It helps in the formation of slag, there by collecting impurities in the weld pool to the surface.

6.Define the term electrode and mention its major classifications. (Dec.2011)Electrode is a tool that created are with work piece in are welding process. The electrodes are

classified as:1. Non consumable electrode,2. Consumable electrode

i). Bare electrode ii). Coated electrode

7.What are the advantages of AC equipments over DC equipment in arc welding? (Apr.2010)Comparison of DC and AC welding process.

S.No. Parameter Direct Current Alternating Current

1. Heat 66% of heat at the positive pole and33% at the negative pole

Heat is uniform both inpositive and negative poles

2. Efficiency Low High (Advantageous)

3. Electrodes Both bare and coated electrodes areused.

Only coated electrodes areused.

4. Base materials Suitable for ferrous and non ferrousmaterials

Suitable for ferrous materials

5. Maintenance cost Higher lower

8. What are the elements added to tungsten electrode to enhance its life in TIG welding process?(Nov 2011).

The non-consumable tungsten electrodes are alloyed with Zirconium or thorium to enhance itslife in TIG welding electrode.

9. Write short notes on transferred and non-transferred arc in plasma arc welding. (May 2013)A. Non-transferred arc process: The arc is formed between the electrode (-) and the water

cooled constricting nozzle (+). Arc plasma comes out of the nozzle as a flame. The arc is independent ofthe work piece and the work piece does not form a part of the electrical circuit.

B. Transferred arc process: The arc is formed between the electrode (-) and the work piece (+).In other words, arc is formed between the electrode and work piece. A transferred arc possesses highenergy density and plasma jet velocity. For this reason it is employed to cut and melt metals.

10. What is the principle of Thermit welding? (Nov.2012)Thermit welding (TW) is a welding process which produces coalescence of metals of heating

them to superheated liquid metal from a chemical reaction between iron oxide and aluminum with orwithout the application of pressure.

11. What is the principle of resistance welding process? (May 2012)In this welding process heat and pressure and applied at the weld surface. The heat is obtained

by the electrical resistance. No filter metal or flux is added.

12. Explain the principle used in percussion welding. (Apr.2011)Percussion welding (PEW) is a resistance welding process which produces coalescence on the

work pieces using heat from an arc produced by a rapid discharge of electrical energy.

13. Write short notes on thermit welding. (Dec.2013)It is a thermo-chemical welding process. The heat required is obtained due to the reaction of

the ‘Thermit mixture’ (Aluminium + Iron oxide). Due to the exothermic reaction intense heat isproduced ( 2200 – 24000C) in less than a minute.

14. Mention the application of friction welding. (Nov.2010)Joints between dissimilar metals can be made: for example.

1. Copper to steel 2. Copper to Aluminium 3. Aluminium to steel or brass and 4. Bronze to Aluminiumor steel

15. Define soldering. (May 2011)It is a method of joining similar or dissimilar metals, with the melting temperature of below

4500C using a filter metal called solder. This method is used for mass production of electroniccomponents.

16. What is brazing? (Dec.2011)Brazing is the process of joining ferrous metals with a non-ferrous filler metal called as spelter

whose melting point is 4270 C. Typical filter metals are brasses with zinc content up to 40%.

17. Why is the flux used in soldering and brazing? (Apr.2010)Flux is the substances added to the metal surface to stop the formation of oxides or similar

contaminants that are formed during the brazing process.

18. List any four filler metals used in brazing. (Dec.2011)1. Silver-base alloys2. Aluminum-silicon alloys3. Copper-zinc (brass) alloys4. Copper-phosphorus alloys5. Nickel alloys

19. What are the different types of brazing. (Dec.2010)1. Torch brazing,2. Induction brazing3. Furnace brazing4. Dip brazing

20. Differentiate between soldering and brazing process. (May 2014)Comparison of soldering and brazing.

Sl.No. Parameter Soldering Brazing1. Strength Less strength joint Strong joint2. Filler metal Solder Spelter

3. Heat source Soldering Iron By gas flame4. Temperature Below 4200C Above 4200C5. Application Electrical connections Pipe joints

21.How does the seam welding is an application of spot welding?(Nov 2015)

1. It is used to make leak proof tanks, drums, and radiators.

2. It is also used for welding thin sheets.


1. Explain with a neat sketch the components of oxyacetylene gas welding equipments.(Dec2014)(Nov 2015)


2. Describe the process of electroslag welding and identify their major applications.(Dec.2014)(Refer page No.2.29 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

3. Explain the process of rotary drive friction welding with its advantages and limitations.(Dec 2014) .(Apr.2010) (May 2013)


4.Briefly explain the principle of operation, advantages and limitations of electron beamWelding. (Dec.2014) . (May 2009) (May 2012)


5. List out the different types of welding process. Briefly explain the working principle of any twowelding process. (Dec.2010)


6. Discuss the gas welding process and the necessary equipments needed with suitable sketches.(Apr.2010), (Dec.2012)


7. Sketch the three type flames in oxy-acetylene welding and state their characteristics. (Nov.2011)(May 2009)


8. Explain the metal arc welding process with a sketch. (Nov.2012, 2013)(Refer page No.2.15 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

9. Explain the principle of resistance welding. Explain the cycle of operation of resistance spotwelding. (May 2009), (Apr.2011), (May 2014)(Nov 2015)


10. Explain the following welding process with a neat sketch (Nov.2013)

(i). Resistance seam welding. (ii). Friction stir welding.(Refer page No.2.36 & 2.53 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

11. Describe with a neat sketch the principle of percussion welding. State its advantages andlimitations. (Apr.2010)


12. Sketch the overall set up of submerged welding process and explain the working principle.Mention its applications. (Nov.2011) (May 2013)


13. With the help of suitable diagrams. Explain the following types of welding.

(1). TIG welding process (2). Electro slag welding process (May 2012)(Refer page No.2.24 & 2.29 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

14. Explain the plasma arc welding process with a neat sketch and list out its advantages. (Nov.2011)

(Nov.2012)(Refer page No.2.40 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

15. Explain the process of transfer arc and non-transfer arc mode of operation in plasma arc weldingwith applications. (Apr.2011)


16. What is the principle of thermit welding? Explain the same with a neat sketch of the weldingarrangements. (May 2012, 2009)(Nov 2015)


17.Explain about the equipment and operations of GTAW process.(Nov 2015)(Refer page No.2.25 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

UNIT -3METAL FORMING PROCESSES


1. Why is drop forging called so? (Dec.2014)When the rolls are released, the ram will fall down and produce a working stroke, then it is said

to be drop forging .

2. What does angle of bite in rolling mean? (Dec.2014)The angle subtended by the centre of the roll with radial force in rolling operations is called

angle of bite or angle of contact.

3. Distinguish between hot working and cold working of metals. (Apr.2011, May 2012)Comparison of Hot working and cold working of metals.

Sl.No. Hot working Cold working1. Usually performed above recrystallisation

TemperaturesCarried out in a temperature region below therecrystallisation temperature

2. No strengthening occurs during hot-working Strength and hardness of the metal areincreased

3. Poor dimensional control Good dimensional control4. Surface finish is not increased Good surface finish of the componenet5. Metal remains soft and ductile during

processThe metal becomes less malleable and ductile.

4. What is meant by recrystallisation temperature? (May 2010)When the metal is heated, the temperature at which old grains start disintegrating and new

grains are formed in the metal is called its Recrystallisation temperature (Tcr).Tcr = (0.3 – 0.5) X Tm

Tm = Melting Temperature

4. Define: Extrusion, as a manufacturing process. (May 2012)Extrusion is defined as a manufacturing process in which a block of metal enclosed in a

contained is forced to flow the opening of a die.

5. What is ironing? (May 2013)It is a process of smoothening or thinning the wall of a shell or cup by forcing the shellthrough a

die and punch in hot or cold state.

6. What is meant by fullering?(apr 2013)It is similar to decreasing the cross – section and increasing the length of the material. To do

this: the bottom fuller is kept in anvil hole with the heated stock over the fuller. The top fuller is thenkept above the stock and then with the sledge hammer and the force is applied on the top fuller toreduce the cross section of job at required point.

7. What is meant by closed die forging? (Nov.2010)The workpiece is deformed between two die halves which carry the impressions of the desired

final shape. The workpiece is deformed under high pressure in a closed cavity, normally used forsmaller component.

8. Mention the different types of shape rolling operation. (Nov.2010, May 2010)1. I-beams 2. Channels 3. Angles 4.Square or hexagonal rods and 5. Tubes

9. What is the principle used in upset forgoing? Name one component produced by this process.(May 2011)(nov 2009)

This is applied to increase the end area of the stock at the expanse of the length. To achievethe length of upsetting, force is applied in a direction parallel to the length axis.Component: Bolts

10.What is the difference between hot and cold forging? (Nov.2013)Comparison of Hot forging and cold forging of metals.

Sl.No. Hot Forging Cold Forging1. Usually performed above recrystallisation

temperatureCarried out in a temperature below therecrystallisation temperature

2. Less force is required Heavy force is required

3. Poor dimensional control Good dimensional control4. Surface finish is not increased Good surface finish of the component

11. Differentiate extrusion and forging. (Nov.2013)Comparison of extrusion and forging of metals.

Sl.No. Extrusion Forging1. Metal is continuously forced into a die

orifice by compressive forceMetal is forced by impact force

2. Suitable for any section of continuous flow Suitable for individual components

12. Distinguish between open-die forging and closed die forging of metals.(nov/dec 2011)Comparisonof open and closed die forging of metals.

Sl.No. Open die forging Closed – die forging1. The workpiece is formed in a flat die The workpiece is deformed under high pressure

in a closed die cavity2. Used for larger components Used for smaller components

3. Poor dimensional control The process provides precision forging with closedimensional tolerance

4. Dies are not expensive Closed dies are expensive

13. Define: the term extrusion ratio. (Nov.2011)The extrusion ratio is defined as the ratio of the cross-sectional area of the billet to the cross-

sectional area of the product. It value is 40:1 for steel.Cross-sectional area of the billet

Extrusion ratio = ---------------------------------------------------Cross-sectional area of the product

14. List two advantages of cold extrusion over hot extrusion.(Nov / Dec 2012)1. No oxidation takes place2. Good mechanical properties due to strain hardening.3. Good surface finish with the use of proper lubricants.

15. Define “up setting “ and “drawing down” in forging operation.(May /June 2014)Upsetting : upsetting is the process of enlarging or bulging the end of the workpiece by the

expance of length.

Drawing down : In drawing down process, thickness of the workpiece is reduced and length andwidth of the workpiece increases.

16. What are the disadvantages of forging process? (Nov 2009)

1. Precise tolerances are less.

2. It is possible warping of the material during the cooling process.

3. Metal gain structure varies.

4. It is possible reactions between the surrounding atmosphere and the metal.

5. The metal surfaces must be clean and free of the scale before forging occurs.

17. List two advantages of cold extrusion over hot extrusion.(Nov2012)

1. Good surface finish.

2. Better dimensional accuracy.

18. Distinguish between wire drawing and tube drawing with sketches. (Nov 2009)

S.No Wire drawing Tube drawing1. It is process used to reduce the diameter of a

Wire by pulling the wire the wire through asingle, or series of, drawing dies.

It is the process to size tube by shrinking a largediameter tube into a smaller one, by drawing thetube through a die.

2. The process is carried out at elevatedtemperatures for large wires to reduceforces.

The process is carried out at room temperaturefor both for both large and small scaleproduction.

3. Mandrels are not used. Mandrels are used.4. It is a slow process. It is faster than wire drawing.

19. List out any four parts that can be manufactured by shape rolling operations. (Apr.10)

a. Straight and long structural shapes

b. Solid bars

c. I-beams

d. Channels

e. Railroad rails


1. With suitable sketches describe indirect and direct extrusion.(Dec 2014) . (May 2011, May 2014)(Apr.2010) (Nov. 2013)


2. Draw a simple sketch showing rolling process and make a short note on deformation of grains inrolling. (Dec.2014)


3. Explain hot working and cold working with their advantages and limitations.(Dec 2014)(Nov 2015)May 2013, Nov.2010)


4. Explain in detail about wire drawing.(Dec 2014)(Nov 2015) (May 2009, May 2013) (May 2010)


5. Working on the metal Lead at room temperature, is considered to be hot working. Why?(Nov.2012)


6. What is smith forging operation? With neat sketches, explain the following smith forgingoperation:

(Dec.2012, Dec.2011)

i). Upsetting ii). Bending

iii).Swaging iv). Fullering

v). Punching and drifting vi). Edging


7. Distinguish, between open die and closed die forging process. (Apr.2010)


8. Distinguish between forging hammers and forging presses. Explain the working of drop hammerwith a neat sketch. (Nov.2011)(Nov 2015)


9. With a neat sketch, explain the working of a pneumatic hammer for forging. (May 2012)


10. What are forging defects? Explain any four defects with the help of sketches.(Ap.2011)


11. Discuss various possible configuration of rolling stand arrangements? (May 2009, 2011, 2012,

2014)(Nov 2015)


12. Briefly explain the strip rolling operation. (May 2013)


13. Explain in details the characteristics of the tube piercing? (May 2009) (May 2010)


14. Explain the defect in rolled parts with suitable examples? (May 2009, May 2010, Dec.2013, June2014)


15. With a neat sketch explain the principle used in tube drawing process. (May 2012, Nov.2010,2011)


16. List four tools used for forging. Sketch any two of them. (May 2012)


17. With suitable sketches, explain the following: (Nov2012)

i). Stages involved in ‘shape rolling’ of structural sections

ii). Cold extrusion forging.

iii). Seamless tube drawing

(Refer page No.3.41& 3.57 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

18. Briefly explain about seamless rolled ring forging. (May 2013)


19. Explain the steps involved in the forging operation. (Nov.2013)


20. Explain the precision forging process with neat sketch and also, compare with closed die forgingprocess. (Nov.2013)


21. With sketches explain the process of manufacturing of connecting rods. (Apr.2011)


26.Explain the advantages and limitations of compound dies over progressive dies.(Nov 2015)


UNIT -4SHEET METAL PROCESSES


1. What is shear angle? Why is it given in punches and dies? (Dec.2014)

The angle about which the vertical tilt is called shear angle.

2. What is flanging? (Dec 2014)

Flanging is a process in which edges bend usually to a 90 degree angle.

3. What is sheet-metal work? (May 2009)

Sheet-metal working operations are performed on thin (Less than 6 mm) sheets, strips or coils ofmetal by means of a set of tools called punch and die on stamping presses. They are always performedas cold working operations.

4. Define the term formability. (Nov.2010)

Formability may be defined as the ease with which a metal can be permanently deformed to anyshape without fracture or any damaged like poor surface finish and wrinkling with less force.

5. Define Spring back. (May 2013, Nov.2013)

During bending operation, plastic deformation of the metal takes place, when the load isremoved from the work-piece, there is some amount of elastic recovery occurs. Due to this the bendangle becomes slightly smaller. This elastic recovery is called spring-back.

6. What is spring back? How is it recovered? (May 2009, 2010, 2014)

In bending operation, due to finite modulus of elasticity of the material. Some elastic recoveryoccurs after the load is removed from the plastically deformed metals. This elastic recovery of themetals is called ‘spring back’. Spring back is usually compensated for by over bending the part.

7. Classify sheet metals dies. (Dec. 2011)

The dies are classified as:

1. Simple dies

2. Compound dies

3. Combination dies

4. Progressive dies,

5. Transfer dies

8.Why is it necessary to provide proper clearance between the punch and die in a shearingoperation?(May 2013)

The space between the punch face and the die face on one side is called ‘ clearance’. It isprovided so that the punch enters into the die cavity and the shearing is completed.

9. What is ‘lancing’ operation that is done on sheet metals? (Nov 2012)

Creating a partial cut in the sheet. So that no material is removed. The material is left attachedto be bent and form a shape, such as a tab ,vent, or louver.

10. What are the advantages of Hydroforming process? (May 2012)

Advantages

1. Low tooling cost

2. Flexibility and ease of operation

3. Low die wear

4. Avoidance of wrinkling and tear of the plate

5. Capability to form complex shapes.

6 .Laminated sheets are also formed.

11. What is peen forming? What are its applications? (Apr 2010,Nov 2010)

Peen forming is a process of well –established surface cleaning. In this process, a stream ofmetal shots is blasted against the surface of the blank to be made into required shape.

12.List the advantages of superplastic forming processes.(Nov 2013)

1. Increased forming rates through material and process.

2. Lower strength is required for the tooling.

3. Complex shapes can be formed.

4. No residual stress occurs in the formed parts.

low cost tooling.

13. What is ironing, as applied to sheet metal work? (Nov 2011)

It is the process of smoothening or thinning the wall of a shell by forcing through a die with apunch, the thickness is also gets reduced.

14. What are the advantages of rubber pad forming process? (Nov 2011)

1. Soft rubber on the top surface of the sheet will not damage or scratch.

2. Accurate and time consuming positioning of the die is not necessary.

3. Only one die is required for the manufacture of a sheet metal part.

4. This offers the opportunity to deform sheet with pre coated surfaces.

5. Sheet with special surface layers like clad – layers are also formed.

15. What is the different between a cut off operation and a parting operation?(may 2014)

Cut-off: separating a part from the remaining sheet without producing any scrap. The punchwill produce a cut line that may be straight curved or angled.

parting: separating a part from the parent sheet by punching away some material between theparts. Scrap is removed in this process.

16.Define Notching. (Dec 2009)

It is the operation through which metal pieces are cut from the edge of a sheet , strip or blank.

17.Define “Embossing”. (Dec 2009)

It is the process of producing required shapes on sheet metal blanks by means of punches anddies.

18. Write the short notes on Hydroforming . (Dec 2009)

Hydroforming is a specialized type of die forming that uses a high pressure hydraulic fluid topress room temperature working material into a die. To hydroform aluminium into a vehicle’s frame rail, a hollow tube of aluminium is placed inside a negative mold that has the shape of the desired endresult. High pressure hydraulic pistons then inject a fluid at very high pressure inside the aluminiumwhich causes it to expand until it matches the mould . The hydroformed aluminium is then removedfrom the mold.

19. List several products that can be made by metal spinning. (Dec 2010)

Production of ashtrays, flowerpots, lampshades, missile and radar units, jet plane componentstanks, air conditioning units and heating plants.

20. Distinguish between piercing and blanking.(NOV 2015)

BLANKING: The cutout portion is the required part in this operation.

PIERCING: The cutout portion is considered as waste and left out portion is the required part.

21. List out test methods for testing formability of material.

1. Formability tests for bulk deformation.

2. Formability test for elastic – plastic deformation

3. Simulative tests for forming operation.

4. Full scale forming tests.


1. What is super plastic forming? Explain with a neat sketch. (Dec.2014) (May 2009)

(Refer page No.470 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

2. Enumerate rubber pad forming with a suitable sketch.(Dec 2014) (May 2012)


3. Enumerate with a neat sketch any two types of stretch forming operations. (Dec.2014)(Nov 2015)


4. Describe magnetic pulse forming with a neat sketch. (Dec.2014) (May 2013)


5. Discuss the method of shearing? Explain the phases involved? (May 2009)


6. Write a note on sheet metal characteristics. (Nov.2010)


7. Describe forming limit diagram. (Nov.2013)


8. Explain the various metal forming operations performed by press with suitable examples.(Apr.2011)


9. Sketch and explain the following sheet metal bending operations with suitable examples.(Nov.2010)

i). Sheet bending using V-die.

ii). Bending edge of a sheet using wiping –die.

iii). Roll bending

iv). Bending a sheet to a round shape using four-slide machine.


10. Explain the basic nomenclature of tube bending with a simple sketch. (May 2013)


11. Describe the shearing and bending operations with suitable examples. (Nov.2010)

(Refer page No. 4.26 & 4.34 , Manufacturing Technology-I By Dr.G.K.Vijayaraghavan.)

12. What are the different types of stretch forming? Explain any one. (May 2013)


13. Describe the metal spinning process with a neat sketch and state its advantages and specific used.(May 2012)


14. With a neat diagram. Explain the principle of explosive forming. (Nov.2012)


15. Discuss with a neat sketch electro-hydraulic forming? (May 2009)


16. Explain the hydro-forming process with neat sketches. Make a brief comparison of this processwith conventional deep drawing. (Nov.2011)(Nov 2015)


17. Explain the single die and multiple operational die with neat sketch. (May 2013)


18. Elucidate process variables in explosive forming. (Nov 2015)


UNIT -5MANUFACTURE OF PLASTIC COMPONENTS


1. What is polymerization? (Nov 2014,May 2013)(Nov 2015)

A polymer is made up of linking thousand of monomer and thus obtaining large modulus iscalled polymerization process.

2. List out any four types of adhesives used in adhesive bonding of plastics.(Dec 2014)

1. Epoxies

2. Methyl methacrylates

3. Silicone adhesives

4. Urethanes.

3. Write a note on thermoplastics. (Dec.2010)

Thermoplastics become soft when heated to 65-3150C. They can be re-moulded without anychange in strength. Thus they can be reshaped while in soft state.

1. Nylon 2. Polyethylene 3. P.V.C. and 4. Teflon

4. Explain the characteristics of thermoplastics. (April/May 2011)

1. Solid materials at room temperature, become viscous liquid when heated.

2. Thermoplastics have a linear or branched molecular structure.

3. They are flexible at ordinary temperatures.

4. At approximately 120 – 1800C, thermoplastics become a pasty/liquid mass.

5. What are elastomers? (Nov/Dec. 2011)

Elastomers are polymers that have high elasticity. They stretch 5 – 10 times, when tensile loadis applied. They regain their original size when the load is removed.

Examples:

1. Natural rubber

2. Poly-butadiene

6. Name two important differences between thermoplastics and thermosetting plastic?

(Nov/Dec 2012).

Difference between thermoplastics and thermosets.

S.No Termoplastics Thermosets1. When subjected to heat and pressure,

they undergo a change in structure.They do not undergo any permanent change by heatand pressure.

2. Structure is made of linear or branchedlinear molecules.

Structure is made of crosslinked molecules

7. What is film blowing? (May/June 2012)

Plastic sheets and films are produced by film blowing. In this process the extruded plastic tube inthe semi solid state is forced by an air stream and blown into long lengths of thin sheets.

8. What is thermal forming? (April/May 2011)

Thermoforming is the process of shaping hot sheets of thermoplastic materials into desiredshape by applying mechanical or pneumatic force. Thus a flat sheet (blank) is converted into acontoured produce of variable thickness.

9. What are the common methods used for forming plastic sheets? (Nov/Dec 2011)

1.Film Blowing

2.Thermoforming

3.Calendaring

10. List the applications of transfer moulding. (Nov/Dec. 2010)

This process is commonly used with thermosetting polymers.

1. Dishes

2. Handles for cooking pots

3. Skis

4. Housing for high-voltage switches

5. Shoe soles

6. Fiber-reinforced parts

11. What are the advantages of transfer moulding? (Nov.2011)

1. Multiple cavities are easier,

2. Lower moulding pressure than compression moulding

3. The parts have gates, so engineering a flow path is possible.

12. What is the basic principle used in calendaring process? (April 2011, 2013)

It is the process of manufacturing plastic sheets. The plastic material which consists of resin.Plasticizers and colour pigments is allowed to pass between a series of hot rolls. The required product isobtained in the form of sheets.

13. What are the different types of compression moulds. (Nov.2013)

1. Positive Type

2. Semi-Positive type

3. Flash or over – Flow Type

14. What is polyethylene? (May 2014)

Polyethylene is a thermoplastic consists of ethylene monomer.

15. What is the difference between hot compression moulding and Transfer moulding.(APR 2011)

S.No Compression moulding Transfer moulding1. The plastic resin is heated and compressed in

the mould itself.The plastic resin is heated in a heatingchamber and forced into the mould cavity by aram

2. Accuracy of the component is less. Accuracy of the component is more

16.Give two examples each for raw material and product made from thermoplastics andthermosetting plastics.(Apr/May 2011)

Products of thermoplastics

S.No. Raw material Products1. Polyethylene Packaging, milk and water bottles2. Polyvinyl chloride(PVC) Floor and wall coverings, automobile

instrument panelsProducts of thermosetting plastics

S.No Raw material Products1. Unsaturated polyesters Varnishes , furniture2. Epoxies and resins Glues,composite materials like fiberglass

17. List out the materials for processing plastics.(Nov 2011)

A) Additives

1. Plasticizers

2. Catalyst

3. Dyes and pigments

4. Initiators

5. Modifiers

6.lubricants

7. Solvents

B) fillers

1. Mica

2. Cloth fibre

3. Asbestos

18.Classify the types of plastics.(Apr2005)

1. Thermoplastics

2. Thermosetting plastics

19. Why is screw injection moulding machine betterthan a ram type injection moulding machine?(Nov2009)

In injection moulding machine ,the pellets are fed into the hopper. The resins are pushed alongwith the heated reciprocating screw. The screw is moved forward to force the plastic material into themould. The screws itself is moving backwards and allowing the accumulation of enough material to fillthe mould. pellets are not used in ram type injection moulding machine.

20. what is the rotational moulding of plastics?(NOV 2009)(NOV 2015)

In this process , a measured quantity of polymer powder is placed in a thin walled mould. Themould is closed and it is rotated about two mutually perpendicular axes as it is heated.


1. What is transfer moulding? Discuss it advantages and limitations. (Dec.2014) (Apr.2010, 2011),(May 2009).(Nov 2015)


2. Explain positive, semi positive and flash type compression moulding. (Dec.2014) (Nov.2012, 2013)


3. Explain the various types of thermoforming method shaping thermoplastics. (Dec.2014)


4. Describe briefly the plunger type injection moulding process for producing plastic components.(Nov.2010, 2012) . (May 2012, 2014)(Nov 2015)


5. Enumerate with a neat sketch working principle of reciprocating screw injection moulding machine.(Apr.2010). (May 2012, 2014)(Nov 2015)


6. Explain briefly with neat sketches two commercially used methods of blow moulding for blowing ofplastic bottles and mention their specific advantages. (May 2009, 2012, 2013), (Nov.2011) (May 2011)


7. What is ‘Rotational moulding”? Explain the same with necessary sketch. Mention also itsapplications. (May 2012, 2013) (Apr.2010)


8. Describe the working principle of film blowing and thermoforming. (Nov.2010)


9. Explain with neat diagrams, the thermoforming process. State its advantages over other processes.

(Nov.2012) (May 2009) .(Nov 2015)


10. Explain how laminated and reinforced plastic manufactured? (Nov.2013) (May 2009)


11. Write down the characteristics of shaping processes for plastics. (Nov.2010)


12. What are the methods of bonding thermoplastics? Explain any one method. (Apr.2010) (May2014)


13. Briefly explain the following methods of bonding of thermoplastics: (Nov.2011)(Nov 2015)

I). Fusion bonding ii). Vibration welding

iii). Solvent bonding iv). Induction welding


vidyaa vikas college of engineering and technology … · 2018-05-08 · vidyaa vikas college of...

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