Deck 9: Foundry Processes and Techniques

Question 1

Which of the following is core hardening process?

A)CO₂ process
B)Cold set process
C)Furan system
D)All of the above

Answer 1

All of the above

Question 2

Blow holes in castings are due to

A)high moisture content of the sand
B)low permeability of sand
C)excessive fine grains and gas producing ingredients
D)any of the above

Answer 2

any of the above

Question 3

When wooden patterns with metallic coating are to be used, the metal sprayed on wooden pattern could be

A)bismuth
B)zinc
C)aluminium
D)any of the above

Answer 3

any of the above

Question 4

Shell moulding can be used for

A)producing thin castings
B)better surface finish
C)tolerances of the order of 0.002 mm per mm
D)all of the above

Question 5

In case of carbondioxide moulding, the binder used is generally

A)coal dust
B)graphite
C)sodium silicate
D)china clay

Question 6

Aluminium castings are not repaired by

A)inert gas metal arc welding
B)braze welding
C)soldering
D)All of the above

Question 7

First step in reclaiming the moulding and core sand is

A)addition of moisture
B)reproportioning of binder
C)separation of metal particles
D)any of the above

Question 8

If ash content of coke used in cupola is high then

A)melting rate will be low
B)castings produced will have blow holes
C)more of flux will be required
D)carbon content of castings will be low

Question 9

Non-uniform distribution of alloying components, inclusions and impurities in an ingot or casting are known as

A)ageing
B)bleeding
C)innoculation
D)segregation

Question 10

Clay used for foundry sand should be

A)kaolinite
B)montmorillonite
C)illite
D)any of the above

Question 11

Phenolic thermo-setting plastics are finding application in pattern making because

A)they do not absorb moisture
B)they are resistant to wear
C)they have all above qualities
D)they are strong

Question 12

The location of riser least depends on

A)the size of core
B)feasibility of directional solidification
C)the metal to be cast
D)design of casting

Question 13

In case of cast steel, the contraction allowance will be least for castings having dimensions

A)upto 600 mm
B)1000 mm to 1800 mm
C)600 to 1000 mm
D)above 1800 mm

Question 14

The "Green sand" is termed so, because

A)it is green in colour
B)it contains moisture
C)none of the above

Question 15

A designer would attempt to avoid bosses and pads in the casting because

A)projections such as bosses and pads can not merge with thinner sections
B)it is difficult to incorporate in pattern
C)they being thicker will take longer to solidify and hence will suffer from residual stresses and coarse grains
D)mould formation is difficult in pressence of boss

Question 16

Padding is

A)a method for production of chilled castings
B)an extra support for thin castings
C)an extra metal added to the original uniform section of the casting
D)none of the above

Question 17

In case of cored aluminium castings, the contraction allowance is

A)more than the normal allowance
B)less than the normal allowance
C)same as the normal allowance

Question 18

Chemical dipping of die casted parts is usually done for

A)flash removal
B)dimensional stability
C)corrosion protection
D)none of the above

Question 19

Head storage capacity of moulding sand can be increased by adding?

A)graphite
B)chromite
C)magnesium powder
D)any of the above

Question 20

Sand grains which give high mould strength are

A)Sub-angular grains
B)Rounded grains
C)Sharp or Angular grains

Question 21

Oil fired furnaces are generally used for the melting of

A)alloy steel
B)cast steel
C)cast iron
D)non-ferrous metals

Question 22

Electric indirect are furnace is normally used for melting of

A)alloy steels
B)cast steels
C)non-ferrous metals
D)all of the above

Question 23

Wood used for pattern making has knots. This is likely to affect

A)warping of the piece
B)machinability of pattern
C)moisture content of wood
D)all of the above

Question 24

As a result of melting of cast iron in cupola, which of the following constituent undergoes least change in its percentage?

A)Manganese
B)Phosphorous
C)Silicon
D)Sulphur

Question 25

Investment casting can be used for which of the following alloys

A)cobalt based satellite
B)Tool steels
C)Hynes super alloys
D)All of the above