Chapter 11

Question 1

involves listening for indications of failure. Temporary
monitoring can be used to detect the formation of cracks in materials during production operations, such as welding and subsequent cooling of the weld region. Almost all materials will emit high-frequency sound when stressed, deformed, or undergoing structural changes, such as the formation or growth of
a crack or defect.

Answer 1

Acoustic Emission:

Question 2

another computer reconstruction technique, this time based on ultrasound reflections from within the part.

Answer 2

Acoustic Holography:

Question 3

an inspection technique that provides a cross-sectional
view of the interior of an object along a plane parallel to the X-ray
beam.

Answer 3

Computed Tomography:

Question 4

links the transducer to the piece to be inspected and
transmits the vibrations into the part because air is a poor transmitter of ultrasonic waves; generally a liquid such as oil or water

Answer 4

Coupling medium

Question 5

a flaw that is clearly unacceptable and a cause for rejection

Answer 5

Critical flaw

Question 6

a means of product assessment that evaluates product quality and ensures the absence of any performance-impairing flaws;
components or assemblies are selected and then subjected to conditions that induce failure

Answer 6

Destructive testing

Question 7

A sufficiently small flaw that does not affect a material throughout its useful lifetime, never changing size or shape

Answer 7

Dormant Flaw

Question 8

When an electrically conductive material is brought
near an alternating-current coil that produces an alternating magnetic field, surface currents (eddy currents) are generated in the material. Cracks, voids, inclusions, and seams can affect the magnitude and direction of the induced eddy currents and can be detected by the electronics

Answer 8

Eddy-Current Testing

Question 9

A function of a material’s chemistry, processing

history, and structural soundness; used for alloy identification, flaw detection, or the assurance of proper processing

Answer 9

Electrical resistivity

Question 10

Flaw-free is an unreasonable expectation for any material. This is said to be the standard for materials, but now that there are
better detection methods this is not possible.

Answer 10

Flaw-free