Materials and Processes Flashcards
1
Q
Tensile Strength
A
Resists being pulled apart end to end and is rated in thousands of PSI. The resulting force is called tension.
2
Q
Yield Strength
A
The metal’s ability to resist being deformed.
3
Q
Shear Strength
A
Metals ability to resist opposing forces.
4
Q
Bearing Strength
A
Metals ability to resist being crushed.
5
Q
Hardness
A
A metal’s ability to resist cutting, penetration, or abrasion.
Can be changed by heat treating or annealing.
6
Q
Malleability
A
Metal’s ability to be bent, formed or shaped without cracking.
Hardness and malleability are considered to be opposite characteristics.
Annealed metals are malleable.
7
Q
Ductility
A
Metal’s ability to be drawn out or stretched without cracking.
Ex. Wire stock, extrusions, and rods
Ductile metals are used for aircraft because of the ease of forming and shock resistance.
8
Q
Brittleness
A
Metals tendency to crack or break under stress
Opposite of ductility and malleability
9
Q
Conductivity
A
Metal’s ability to transfer temperature or electricity.
When metal conducts heat, it is being thermally conductive.
10
Q
Elasticity
A
Metal’s ability to return to its original shape after stretching or bending
11
Q
Toughness
A
Metal’s ability to resist breaking or tearing when bent or stretched.
12
Q
Fusibility
A
Metal’s ability to be joined by heating.
13
Q
Density
A
Metal’s mass.
The denser a metals is, the heavier it is.
14
Q
Thermal Expansion
A
Metal’s ability to expand when heated and contract when cooled.
15
Q
Ferrous Metals
A
An iron alloy that contains a controlled amount of carbon
Magnetic
16
Q
Nonferrous
A
An alloy containing no iron.
Aluminum, copper, titanium, and magnesium.
17
Q
Wrought Forming
A
Physically working metal into a shape.
Both hot working and cold working are considered wrought forming.
18
Q
Hot Working
A
Working metals while it is heated to near it’s critical temperature
Rolling
Forging
19
Q
Cold Working
A
Shaping, rolling, or drawing metal below it’s critical temperature.
Cold rolling
Bending
Cold drawing
20
Q
Strain Hardening
A
Mechanically working a metal below it’s critical temperature, altering the grain structure and hardening the metal.
Indicated by the letter “H” after the allow number if done by design. Example: 5052-H
Cold working or work hardening.
21
Q
Magnetic particle inspection is used primarily to detect what?
A
Flaws on or near the surface.
22
Q
Liquid penetrant inspection methods may be used on which of the following?
A
Ferrous and nonferrous metals and nonporous plastics.
23
Q
Which of these nondestructive testing methods is suitable for the inspection of most metals, plastics, and ceramics for surface and subsurface defects?
A
Ultrasonic Inspection.
24
Q
Which of the following defects are not acceptable for metal lines?
A
Dents in straight section that are 20% of tube diameter.
25
What nondestructive testing method requires little or no part preparation, is used to detect surface or near-surface defects in most metals, and may also be used to separate metals or alloys and their heat-treated conditions?
Eddy Current Inspection
26
What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks and other defects?
The continuous method of magnetic particle inspection.
27
Which of the following factors are considered essential knowledge for X.ray exposure?
Material thickness and density and the type of defect to be detected.
Material thickness and density
Shape and size of the object
Type of defect to be detected
Characteristics of X-ray machine used
Exposure distance
Exposure angle
Film characteristics
Type of intensifying screen, if used
The type of defect to be detected
28
The testing medium that is generally used in magnetic particle inspection utilizes a ferromagnetic material that has what?
High permeability and low retentivity.
29
Which statement relating to the residual magnetizing inspection method is true?
It may be used with steels which have been heat treated for stressed applications.
30
A mechanic has completed a bonded honeycomb repair using the potted compound repair technique. What nondestructive testing method is used to determine the soundness of the repair after the repair has cured?
Metallic ring test.
31
What two types of indicating mediums are available for magnetic particle inspection?
Wet and dry process materials.
32
Which of the following materials may be inspected using the magnetic particle inspection method?
Iron alloys.
33
One way a part may be demagnetized after magnetic particle inspection is by what?
Slowly moving the part out of an AC magnetic field of sufficient strength.
34
Which type crack can be detected by magnetic particle inspection using either circular or longitudinal magnetization?
45 degrees.
35
Which of the following methods may be suitable to use to detect cracks open to the surface in aluminum forgings and castings?
Dye penetrant inspection and eddy current inspection.
36
To detect a minute crack using dye penetrant inspection usually requires what?
A longer than normal penetrating time.
37
Which of the following is a main determinant of the dwell time to use when conducting a dye or fluorescent penetrant inspection?
The size and shape of the discontinuities being looked for.
38
When checking an item with the magnetic particle inspection method, circular and longitudinal magnetization should be used to what?
Reveal all possible defects.
39
In magnetic particle inspection, a flaw that is perpendicular to the magnetic field flux lines generally causes what?
A large disruption in the magnetic field.
40
If dye penetrant inspection indications are not sharp and clear, the most probable cause is that the part what?
Was not thoroughly washed before the developer was applied.
41
(1) An aircraft part may be demagnetized by subjecting it to a magnetizing force from alternating current that is gradually reduced in strength
(2) An aircraft part may be demagnetized by subjecting it to a magnetizing force from a direct current that is alternately reversed in direction and gradually reduced in strength
(1) True
(2) True
42
The pattern for an inclusion is magnetic particle buildup forming what?
Parallel lines.
43
A part which is being prepared for dye penetrant inspection should be cleaned with what?
A volatile petroleum-base solvent.
44
Under magnetic particle inspection, a part will be identified as having fatigue crack under which condition?
The discontinuity is found in a highly stressed area of the part.
45
In performing a dye penetrant inspection, the developer what?
Acts as a blotter to produce a visible indication.
46
What defects will be detected by magnetizing a part using continuous longitudinal magnetization with a cable?
Defects perpendicular to the long axis of the part.
47
Circular magnetization of a part can be used to detect which defects?
Defects parallel to the long axis of the part.
48
(1) In nondestructive testing, a discontinuity may be defined as an interruption in the normal physical structure or configuration of a part.
(2) A discontinuity may or may not affect the usefulness of a part.
(1) true
(2) true
49
What type of corrosion may attack the grain bound-aries of aluminum alloys when the heat treatment process has been improperly accomplished?
Intergranular
50
Which of the following describe the effects of annealing steel and aluminum alloys?
Decreasing internal stresses and softening of the metal.
51
Which heat-treating process of metal produces a hard, wear resistant surface over a strong, tough core?
Case hardening
A heat treatment process for steel in which the surface is hardened to make it wear resistant, but the inside of the metal remains strong and tough.
52
Which heat-treating operation would be performed when the surface of the metal is changed chemically by introducing a high carbide or nitride content?
Case hardening.
53
Normalizing is a process of heat treating what?
Iron-base metals only.
54
Which of the following occurs when a mechanical force such as rolling, hammering, or bending is repeatedly applied to most metals at room temperature?
The metals become dumb as shit and strain or work hardened or cold worked.
55
The reheating of a heat treated metal, such as with a welding torch what?
Can significantly alter a metal's properties in the reheated area.
56
Why is steel tempered after being hardened?
To relieve its internal stresses and reduce it brittleness.
57
What aluminum alloy designations indicate that the metal has received no hardening or tempering treatment?
3003-F
58
Which material cannot be heat treated repeatedly without harmful effects?
Clad aluminum alloy.
59
What is descriptive of the annealing process of steel during and after it has been annealed?
Slow cooling; low strength.
60
Torque values for aircraft bolts normally consider what?
The threads to be clean and dry.
61
What is generally used in the construction of aircraft exhaust collectors, stacks, and manifolds?
Stainless steel.
62
What metal has special short-time heat properties and is used in the construction of aircraft firewalls?
Titanium alloy.
63
Unless otherwise specified or required, aircraft bolts should be installed so that the bolthead is what?
Upward, or in a forward direction.
64
Alclad is a metal consisting of what?
Pure aluminum surface layers on an aluminum alloy core.
65
A fiber-type, self-locking nut must never be used on an aircraft if the bolt is what?
Subject to rotation.
66
Self-locking nuts may be used on aircraft provided that what?
The bolt or nut is not subject to rotation.
67
The society of automotive engineers (SAE) and the American Iron and Steel Institute use a numerical index system to identify the composition of various steels. In the number "4130" designating chromium molybdenium steel, the first digit indicates the what?
Basic alloying element.
68
8262. (Refer to Figure 42) Which of the bolthead code markings shown identifies an AN corrosion resistant steel?
3
69
Aircraft bolts with a cross or asterisk marked on the bolthead are what?
Standard steel bolts.
70
Which statement regarding aircraft bolts is correct?
In general, bolt grip lengths should equal the material thickness.
71
Generally speaking, bolt grip lengths should be what?
Equal to the thickness of the material which is fastened together.
72
When the specific torque value for nuts is not given, where can the recommended torque value be found?
AC 43. 13-1B
73
8267 (Refer to figure 43) Identify the clevis bolt illustrated.
3
74
A particular component is attached to the aircraft structure by the use of an aircraft bolt and a castle tension nut combination. If the cotter pin hole does not align within the recommended torque range, the acceptable practice is to what?
Change washers and try again.
75
A bolt with a single raised dash on the head is classified as an what?
AN corrosion-resistant steel bolt.
76
How is a clevis bolt used with a fork-end cable terminal secured?
With a shear nut tightened to a snug fit, but with no strain imposed on the fork and safetied with a cotter pin.
77
Where is an AN clevis bolt used in an airplane?
Only for shear load applications.
78
A bolt with an X inside a triangle on the head is classified as an what?
NAS close tolerance bolt.
79
The core material of Alclard 2024-T4 is what?
Heat-treated aluminum alloy, and the surface material is commercially pure aluminum.
80
The aluminum code number 1100 identifies what type of alluminum?
99 percent commercially pure aluminum.
81
Aircraft bolts are usually manufactured with a what?
Class 3 fit for threads.
82
In the four digit aluminum index system number 2024, the first digit indicates what?
The major alloying element.
83
How is the locking feature of the fiber-type locknut obtained?
By the use of an unthreaded fiber locking insert.
84
Why should an aircraft maintenance technician be familiar with weld nomenclature?
In order to gain familiarity with the welding technique, filler material, and temperature range used.
85
8278 (Refer to figure 44.) Identify the weld caused by an excessive amount of acetylene.
3
86
8279 (Refer to figure 44) Select the illustration which depicts a cold weld.
2
87
Why is it considered good practice to normalize a part after welding?
To relieve internal stresses developed within the base metal.
88
Holes and a few projecting globules are found in a weld. What action should be taken?
Remove all the old weld, and reweld the joint.
89
Which condition indicates a part has cooled too quickly after being welded?
Cracking adjacent to the weld.
90
Select a characteristic of a good gas weld.
The weld should taper off smoothly into the base metal.
91
One characteristic of a good weld is that no oxide should be formed on the base metal at a distance from the weld of more than what?
1/2 inch
92
In examining and evaluating a welded joint, a mechanic should be familiar with what?
Likely ambient exposure conditions and intended use of the part, along with type of weld and original part material composition.
93
8285 (Refer to figure 45) What type of weld is shown at A?
A single butt weld.
94
8286 (Refer to figure 45) What type of weld is shown at B?
A double butt weld.
95
8287 (Refer to figure 45) What type of weld is shown at G?
Lap welds.
96
On a fillet weld, the penetration requirement includes what percentage(s) of the base metal thickness?
25 to 50 percent.
97
Which tool can be used to measure the alignment of a rotor shaft or the plane of rotation of a disk?
Dial indicator.
98
8290 (Refer to figure 46) The measurement reading on the illustrated micrometer is what?
0.2851
99
Identify the correct statement.
Dividers do not provide a reading when used as a measuring device.
100
8292 (Refer to figure 47) What is the measurement reading on the vernier caliper scale?
1.436
101
Which tool is used to measure the clearance between a surface plate and a relatively narrow surface being checked for flatness?
Thickness gauge.
102
Which number represents the vernier scale graduation of a micrometer?
0.0001
103
Which tool is used to find the center of a shaft or other cylindrical work?
Combination set.
104
8296 (Refer to figure 48) What does the micrometer read?
.3004
105
If it is necessary to accurately measure the diameter of a hole approximately 1/4 inch in diameter, the mechanic should use a what?
Small hole gauge and determine the size of the hole by taking a micrometer reading of the ball end of the gauge.
106
8298 (Refer to figure 49) The measurement reading on the micrometer is what?
0.2792
107
What tool is generally used to set a divider to an exact dimension?
Machinist scale
108
What tool is generally used to calibrate a micrometer or check its accuracy?
Gauge block
109
What precision measuring tool is used for measuring crankpin and main bearing journals for out of round wear?
Micrometer caliper.
110
The side clearances of piston rings are measured with a what?
Thickness gauge.
111
How can the dimensional inspection of a bearing in a rocker arm be accomplished?
Telescopic gauge and micrometer
112
The twist of a connecting rod is checked by installing push-fit arbors in both ends, supported by parallel steel bars on a surface plate. Measurements are taken between the arbor and the parallel bar with a what?
Thickness gauge
113
What may be used to check the stem on a poppet-type valve for stretch?
Micrometer
114
Which tool can be used to determine piston pin out-of-round wear?
Micrometer caliper.
