8 The Casting Process

Question 1

NDT method used for service examination of castings

Answer 1

Penetrant PT

Question 2

Testing methods that may be needed to detect internal defect’s regardless of the material or type of casting

Answer 2

Radiographic RT

Ultrasonic testing UT

Question 3

The rough surfaces of any casting also can produce problems in this ultrasonic device

Answer 3

Transducer coupling

Question 4

This method is used extensively in the examination of critical coolant passages in turbine engine blades to measure thickness

Answer 4

Ultrasonic UT

Question 5

Methods used to detect leading and trailing edge cracks before and during service of turbine blades

Answer 5

Eddy current ET

Penetrant PT

Question 6

The first step in the casting process is to create this which represents the finished product

Answer 6

Pattern

Question 7

The pattern may have attachments or grooves in the mold to serve as channels for flow of material into the cavity these are called

Answer 7

Runners

Question 8

In some casting processes this is made to flow into close contact with the pattern and that has sufficient strength to maintain that position

Answer 8

Mold

Question 9

An opening to the outside of the mold is called

Answer 9

Spruce

Question 10

Pinetree shaped structures in solidification seals a small pockets of liquid to freeze later

Answer 10

Dendrites

Question 11

Large grains in castings cause diffraction effect with which method

Answer 11

Radiografic RT

Question 12

In castings reflection from grain boundaries cause problems with this method

Answer 12

Ultrasonic UT

Question 13

Low melting or fusing alloys are known as

Answer 13

Eutectic Alloys

Question 14

Some of the most important problems connected with the casting process are those of

Answer 14

Shrinkage

Question 15

The freezing of a liquid from the outside toward the center

Answer 15

Progressive solidification

Question 16

The freezing from one part of a casting to another, such as from one end to the other end is known as

Answer 16

Directional solidification

Question 17

The point where metal is poured into the mold is known as

Answer 17

Feed head

Question 18

In casting, the highest temperature areas immediately after pouring are called

Answer 18

Hot Spots

Question 19

In a casting isolated sections that freeze early, that may disturb good directional solidification result in

Answer 19

Shrinks, porosity, cracks, ruptures, or warping

Question 20

Usually located at points of greatest sectional dimension in castings

Answer 20

Hot spots

Question 21

Used to pour and transport hot molten metal from the melting equipment to the molds

Answer 21

Ladle

Question 22

Drops of splashing metal lose heat, freeze, and are then entrapped as globules that cannot join completely with the metal which freezes later and are held partially by mechanical bond

Answer 22

Cold shots

Question 23

Thin sections that cool to rapidly in contact with the mold walls may freeze off before the metal travels it’s complete path, or metal flowing in one direction may solidify and then be met by metal flowing through another path to form a defect known as a

Answer 23

Cold shut

Question 24

Metal is fed into the cavity that shapes the casting through a system consisting of pouring basins, a down spruce, runners, and ingates

Answer 24

Gating system

Question 25

Used to replace the contraction of solidification and to promote good directional solidification

Answer 25

Risers

Question 26

Heat absorbing devices inserted in the mold near the cavity to help and directional solidification

Answer 26

Chills

Question 27

Fast cooling during and after solidification retards grain growth and thus produces a harder, stronger structure using these

Answer 27

Chills

Question 28

The bottom part of the flask is called

Answer 28

Drag

Question 29

The upper part of the flask is known as

Answer 29

Cope

Question 30

A mixture of sand, clay, and moisture is

Answer 30

Green sand

Question 31

Used to facilitate the removal from the mold medium

Answer 31

Draft angles

Question 32

Where the largest two dimensions are in a single plane is this kind of pattern

Answer 32

Flat back

Question 33

Require separation along two or more planes for removal of the pattern to produce the casting cavity

Answer 33

Irregular parting

Question 34

Open face containers that hold the molten medium as it is packed around the pattern.

Answer 34

Flasks

Question 35

Snap, pop off, and slip are all types of these

Answer 35

Flasks

Question 36

When molds are constructed with removable flasks these are placed over them to maintain alignment during pouring

Answer 36

Jackets

Question 37

Bodies of mold material, usually in the form of inserts that exclude metal flow to form internal surfaces in a casting

Answer 37

Cores

Question 38

When a substantial portion of a core is enclosed in a casting, this method is frequently used to determine whether or not the core shifted during casting, or to be certain that all the core material has been successfully removed after casting

Answer 38

Radiography RT

Question 39

Very large or long slender cores that might give way under pressure of the flowing metal or sometimes give additional support by the use of

Answer 39

Chaplets

Question 40

This method used to examine the finished casting can reveal discontinuities surrounding chaplet regions and indicate whether the chaplet completely fused with the base metal

Answer 40

Radiography RT

Question 41

With the mold open, the inside surfaces are subjected to heat from torches, radiant lamps, hot dry air, or electric heating elements to form a dry insulation around the mold cavity this is known as

Answer 41

Skin Drying

Question 42

A mold made by covering the heated metal pattern with sand that it's mixed with small particles of a thermosetting plastic

Answer 42

Shell Mold

Question 43

Mold casting that is used mostly for the shaping of aluminum, copper, magnesium, and zinc alloys

Answer 43

Permanent mold casting

Question 44

Mold casting when pressure is applied to the liquid metal to cause it to flow rapidly and uniformly into the cavity of the mold, or die

Answer 44

Die Casting

Question 45

Investment casting is also known as

Answer 45

Lost wax casting

Question 46

Investment castings of high-strength alloy turbine buckets for gas turbines require NDT methods of

Answer 46

Radiographic RT and penetrant PT

Question 47

Casting procedure makes use of the rotating mold to develop forces acting on the metal to improve its density towards the outside of the mold

Answer 47

Centrifugal Casting

Question 48

Method used to produce cast bar

Answer 48

Continuous casting

Question 49

This melting equipment is charged through a door above the melting zone with layers of coke, iron, and limestone and maybe operated continuously by taking off melted iron is it accumulates in the well at the bottom

Answer 49

Cupola

Question 50

Fractured forming in metal during solidification resulting from restrained contraction is called

Answer 50

Hot tear