cap 13 Materiales

Question 1

1. Nondestructive testing may be applied at which of the following stages of a product’s life cycle?

a. During raw product, castings, forgings, extrusions, and so on.
b. After secondary processing, machining, welding, and so on.
c. After the product has been placed in service.
d. At any stage of a component’s life cycle.

Answer 1

d. At any stage of a component’s life cycle.

Question 2

2. An inspection technique that can be used to monitor or offer insight into a material’s composition, anisotropy, texture, residual stress, and so on, by determining speed of mechanical wave propagation is referred to as:

a. acoustic emission monitoring.
b. acoustic velocity monitoring.
c. velocity factoring monitoring.
d. density propagation monitoring.

Answer 2

b. acoustic velocity monitoring.

Question 3

3. Metallurgical properties, such as grain size, cleanliness or inclusion content, hardness, fracture toughness, and strength, have all been shown to experimentally change a material’s:

a. material weight.
b. piezoelectric constant.
c. acoustic velocity.
d. melting temperature.

Answer 3

c. acoustic velocity.

Question 4

4. Electrical conductivity of a metal is commonly evaluated using one of two electromagnetic techniques, eddy current or:

a. acoustic emission.
b. ultrasonics
c. alternating current potential drop.
d. electronic thermal gradient potential.

Answer 4

c. alternating current potential drop.

Question 5

5. The energy levels of fluoresced X-rays identify the elemental atom, and the number of fluoresced X-rays in a given time interval gives a semi-quantitative measure of the element’s concentration in what type of test?

a. K-edge spectroscopy.
b. Mass spectroscopy.
c. Raman spectroscopy.
d. Positive material identification.

Answer 5

d. Positive material identification.

Question 6

6. A powerful technique in polymer characterization for identifying molecular compounds and the type of chemical bonds present in a sample is:

a. K-edge spectroscopy.
b. Mass spectroscopy.
c. Raman spectroscopy.
d. Positive material identification.

Answer 6

c. Raman spectroscopy.

Question 7

7. Abrasive wear properties, fatigue resistance, and
   the base metal strength of a steel component can
   be improved by increasing the hardness of its
   exterior in a process called:

a. age hardening.
b. case hardening.
c. chrome plating.
d. titanium plating.

Answer 7

b. case hardening.

Question 8

8. NDT technique are often used to verify casting
   integrity and these inspections are usually based
   on a quality class or level. The class is the degree
   or thoroughness of testing and different levels
   generally correspond to:

a. acceptable discontinuity locations.
b. different casting processes.
c. acceptable discontinuity sizes.
d. different casting materials.

Answer 8

c. acceptable discontinuity sizes.

Question 9

9. Typical discontinuities including undercut, arc strikes, lamellar tearing, and cracks are often found in what type of joints or bonds?

a. Chemical bonds.
b. Friction-stir welded joints.
c. Arc-welded joints.
d. Bolted joints.

Answer 9

c. Arc-welded joints.

Question 10

10. When examining rotating, reciprocating, or
    electromagnetic machinery to seek problems such as vane/impeller, electric motor, and belt drive problems, the method most commonly used would be:

a. acoustic emisión.
b. ultrasonics.
c. radiography.
d. vibration analysis.

Answer 10

d. vibration analysis.

Question 11

11. NDT is useful for detecting and monitoring products during their service life, as they tend to
    deteriorate or fail when placed into service.
    Common causes of material failure include all but which of the following?

a. Excessive static or dynamic loading.
b. Excessive anodic protection.
c. Electrochemical action.
d. Embrittlement and thermal cycling.

Answer 11

b. Excessive anodic protection.

Question 12

12. A progressive mechanism of material failure in
    which a crack initiates, often at a surface discontinuity, then propagates under repeated or fluctuating stress cycles, is called:

a. cráter cracking.
b. stress corrosion cracking.
c. weld root cracking.
d. fatigue cracking.

Answer 12

d. fatigue cracking.