basic questions - engineering (autosaved)

7/27/2019 Basic Questions - Engineering (Autosaved)

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a.Milling.b.Turning.c. Drilling.d.Grinding.e.Honing.f. Lapping.g.Planning and shaping.

6.Name some of the Non traditional Machining process.a.Electrical discharge machining.( EDM)b.Ultrasonic Machining.

7.Name some of the Fabrication and joining process.a.Tungsten inert - gas Welding (TIG)b.Metal insert gas welding.c. Gas welding.d.Brazing.e.Soldering.f. Mechanical Fastening.

8.Expand DFA?Design for Assembly.

9.Expand DFM?Design for Manufacturing.

10.Expand FMEA?Failure mode and Effects Analysis.


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11.Expand QFD?

Quality Function Deployment.

12.Expand DOE?Design of Experiments.

13.What are the uses of DFA?DFA techniques are capable of identifying opportunities for part count

reduction and potential costs of manufacture and assembly.

14.Name some of the process selections parameters to be considered?a.Product quantity.b.Tooling Costs.c. Tolerance requirements.d.Surface finish needs.e.Bulk Treatment and Surface treatments.f. Processing times.g.Material Costs and availability.h.Material to Process capability.i.Component form and dimensions.

15.Name some of the materials which is found to be difficult for sandcasting.

Lead, Tin and Zinc alloys.

16.Some of the typical applications of sand Casting.


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a.Engine blocksb.Machine tool bases.c. Pump housings.d.Cylinder heads.

17.Materials used for Gravity die casting.Usually non ferrous metals, for example: copper, Aluminum,

Magnesium etc.

18.What are the two types of pressure die castings.?a.Cold Chamber die casting. Used for high melting temp metals.b.Hot Chamber die casting. Used for low melting temp metals (Zinc,

Magnesium).

19.What are the uses of Investment casting.a.Very complex castings with unusual internal configurations Possible.b.High strength castings are produced.c. Practical way of producing threads in hard to machine materials, or

where thread design is unusual.

d. Minimum section ranges from 0.25 to 1.00mm depending uponsize.

e. Complex shapes may be assembled from several simpler shapes.

20.Explain Injection molding?Granules of Un polymerized material are heated and then forced, under

pressure into the die cavity.

21.Materials used for injection molding?


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Mostly thermo plastics, but thermosets, composites and elastomers are

possible.

22.What are thermo plastics?Plastics which are re usable are called thermo plastics.

23.Applications for injection molding components?a.High precision, complex plastic components.b.Electrical Parts.c. Fittings.d.Containers.e.Housings.f. Tool handles.

24.What are the minimum wall thicknesses that can be molded ininjection molding?

Minimum 0.4 mm for thermo plastics and 1mm for thermo setting

materials.

25.Expand the following?a.ABS - Acrylonitrile butadiene styrene.b.PMMA polymethylmethaacrylate.c. PC poly carbonate.d.PP poly propylenee.PVC poly vinyl chloride.f. PA poly amide.g.PETP polyethyleneteraphthalate.


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26.Give some examples of Blow Molding?

a.Pet bottlesb.Hollow plastic parts with relatively thin walls.c. Bumpers.d.Ducting.

27.Minimum wall thickness in blow molding?0.25mm

28.Hot forging examples?a.Connecting rods.b.Crank shafts.c. Axle shafts.d.Tool bodies.

29.Minimum wall thickness of hot forgings?3mm

30.What is the basic Material property required for forging?Material must be ductile at forging temperatures.

31.Typical applications of cold forgings?a.Fasteners.b. Tool sockets.c. Gear blanks.


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32.Name some of the sheet metal shearing?

a.Cutting.b.Piercing.c. Blanking.d.Fine blanking.

33.Name some of the Sheet metal forming?a.Deep drawing.b.Bending.c. Stretch forming.d.Roll forming.

34.Strength of the powder metallurgical parts depends on?Product Strength determined by powder size, compacting pressure,

sintering time and temperature.

35.What is CRCA?Cold Rolled cleared annealed.

36.What is HRCA?Hot rolled cleared annealed.

37.What are the types of bending?a.Air bendingb.3 point bending.c. Radius forming.d.Joggle.e.Offset forming.


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38.What is the difference between piercing and blanking?In piercing operation, the component which is falling from the die is a

waste.

In blanking operation, the component which is on the die is a waste.

39.Surface roughness value achieved in turning operation?Ra = 0.32 to 25 microns.

40.How the machining time is is calculated in turning operation?

Machining time = Length to be turned

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Feed per minute.

41.What are the types of lathes?a.Center lathe.b.Turret lathe.c. Computer Numerical control lathe.d.Vertical lathe.

42.What are the two types of milling process used in milling?a.Climb milling. (up milling)b.Down milling. (Down milling).

43.Name some of the Centre less grinding process components are used?a.Guide rods.


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b.Shafts.

44.What are the parameters to be considered for a grinding wheelselection?

a.Material to be ground.b.Type of bonds used for the grinding wheel.c. Structure of the grinding wheel.d.Hardness of the material to be ground.

45.What type of grinding wheels is used for grinding steel components?Aluminum oxide.

46.What type of grinding wheels is used for grinding steel components?Silicon Carbide.

47.What type of grinding wheels will be choosed for the following?a.Soft materials - hard wheels (coarser grains).b.Hard materials Soft wheels (finer grains).

48.What is the minimum amount of material removed during Lappingoperation?

0.005 to 0.01mm

49.What is the material used for preparing the electrode in wire cuttingProcess?

Copper wire.

50.What are the tolerances that can be achieved in wire cutting process?


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0.005 to 0.125mm

51.What is the roughness value achieved in a wire cutting process?0.05 to 12.5microns.

52. What is the material used for preparing the electrode in an EDMProcess (Sparking)?

Copper.

53.What is the roughness value achieved in a wire cutting process?0.2 to 6.3microns.

54.Materials used for ultrasonic Welding?Brittle hard materials are preferred to Ductile. For Example: Ceramics,

Plastics, Precious stones and glass.

55.Where is tig welding used?Most non ferrous material (except zinc), for example Aluminum,nickel,

and magnesium.

Dissimilar materials are difficult to weld.

56.Where is the tig welding used?Butt, Lap, fillet and edges.

57.Where is Mig welding used?Carbon, Low alloy steel and stainless Steels.



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58.Where is Spot welding used?

Low carbon steels. Not recommended for cast iron, Low melting points

metals and high carbon steels.

59.What is minimum and Maximum sheet thickness required for spotwelding?

Minimum Sheet thickness 0.3mm ; Max - 6mm

60.Where is Gas welding used?Carbon, Low alloy steel, stainless Steels and Cast iron.


61.What is minimum and Maximum sheet thickness required for Gaswelding?

Minimum Sheet thickness 0.5mm (3mm for cast iron) ; Max - 30mm

for carbon steel and cast iron).

62.What is Alpha iron?The body centered cubic form of pure iron, Stable below 1025Degree

centigrade.

63.What is austenite?A sold solution of iron and carbon and some times other elements in

which gamma iron, characterized by a face centered crystal structure, isthe solvent.

64.What is cold rolled steel?Steel which has been passed through rollers at steel mills to size it

accurately and smoothly.


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65.What is a gray cast iron?A cast iron gives a gray fracture due to the presence of flake graphite.

66.What is high carbon steel?Steel that has more than 0.6% carbon.

67.What is low carbon steel?Steel containing less than 0.3% carbon.

68.What is Marten site?An unstable constituent that is formed by heating and quenching steel.

69.What is medium carbon steel?Steel containing between 0.3 to 0.6% carbon.

70.What is pig iron ?Iron produced from ore in the blast furnace, basic raw material from

which all cast iron, wrought iron and steel are made. Usually contains

about 4.5% carbon and impurities such as phosphorus , silicon and

sulphur.

71.Material composition of stain less steel?Alloy steel containing iron, atleast 11% chromium , nickel molybdenum

and 0.1 1% carbon.

72.Define brittleness?


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The property of the materials does not deform under load, but to break

suddenly, for example, cast iron and glass are brittle. Brittleness is

opposite to Plasticity.

73.Define Compressive strength?The maximum stress that can be applied to a brittle material in

compression without fracture.

74.Define Creep?Slow plastic deformation in steel and Most structural metals caused by

prolonged stress under yield point at elevated temperature.

75.What is damping capacity?The ability to absorb vibration. More accurately defined as the amount

of work dissipated into heat by a unit volume of material during a

completely reverse cycle of unit stress.

76.Define Ductility?The property of a material to deform permanently or to exhibit

plasticity, elongation or bending or twisting without rupture( Breaking

or cracking) while under tension.

77.Define elasticity?The ability of a material to return to its original form after the load is

removed.

78.Define Factor of Safety?The ratio of the damaging stress to working stress.


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79.What is fatigue in metals?The tendency in a metal to fail, breaking or cracking under conditions

of repeated cyclical stressing that takes place well below the ultimate

tensile strength.

80.What is fatigue strength?The amount of stress that can applied to a metal without failure while it

is subjected to ten million or more cycles of load reversals. In Mild

steel, the fatigue strength is 50% of the tensile strength.

81.What is Hardenability?The property that determines the depth and distribution of hardness in

a ferrous alloy induced by heating and quenching.

82.What is machinability?The relative ease of machining that is related to the hardness of the

material to be cut.

83.What is malleability?In Metals, The property of being able to undergo mechanical

deformation(flattened by rolling or hammering) without rupturing or

developing a marked increase in resistance to change of shape.

84.What is modulus of Elasticity or Youngs modulus?A measure of the rigidity of metals. Ratio of stress, within propotional

limit, to corresponding strain.

85.What is plasticity?


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The quality of material such that it can be deformed without breaking.

Clay is completely a plastic material.

86.What is permeability?In casting of metals, the term used to define the porosity of foundry

sands in moulds and the ability of trapped gases to escape through the

sand.

87.What is plastic deformation?Deformation that does or will remain permanent after the removal of

load which caused it.

88.What is resilience?Ability of a material to store elastic energy without permanent

deformation.

89.What is shear Load?A load that tends to force materials apart by application of side slip

action.

90.What is stiffness?The ability of a metal or shape to resist elastic deformation. For

identical shapes, the stiffness is proportional to the modulus ofelasticity.

91.What is toughness?


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Ability of a metal to absorb energy and deform plastically before

fracturing.

92.What is annealing?A heat treatment in which metals are heated and then cooled very

slowly for the purpose of decreasing hardness. Also used to remove

stresses resulting from cold working and refine and make uniform the

microscopic internal structures of metals.

93.What is anodizing?To Subject to metal to electrolytic action, as takes place at the anode of

a cell, in order to coat it with a protective or decorative film. Used for

non ferrous metals.

94.What is carburizing?A process that introduces carbon into a heated solid ferrous alloy by

having it in contact with a carbonaceous material.

95.What is case hardening?Heating a steel in the presence of a solid, liquid or gs, rich in carbon. In

order to enable the surface to be hardened, while retaining a tough,

ductile core.

96.What is flame hardening?Process of hardening by which steel or cast iron is raised to a high

temperature by a gas torch flame and immediately quenched.

97.What is induction hardening?


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Heating the surface of cast iron or tool steel by means of

electromagnetic currents followed by quench.

98.What is nitriding?A process of case hardening in which a special ferrous alloy is heated in

an atmosphere of ammonia or is in contact with any other nitrogenous

material. By this surface hardening is achieved the absorption of

nitrogen with out quenching.

99.What is Normalising?Process applied to iron base alloys, such as steel, to refine the grain

structure and remove the effects of previous processing for example

hot rolling.

100. What is sub zero treatment?Method of heat treatment of steel, introducing a cooling period or

periods at a temperature well below freezing point, the object being to

ensure complete transformation of austenite to marten site.

101. What is tempering steel?Heat treatment designed to relieve the stresses and brittleness set upin carbon or alloy steel tools and other parts after hardening and to

restore the required degree of toughness and ductility to hardened

steel.


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