Materials & Processes Flashcards
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 molybdenum steel, the first digit indicates the
Basic alloying element
What precision measuring tool is used for measuring crankpin and main bearing journals for out-of-round wear?
micrometer caliper
Magnetic particle inspection is used primarily to detect
Flaws on or near the surface
Aircraft bolts with a cross asterisk marked on the bolthead are
Standard steel bolts
A part which is being prepared for dye penetrant inspection should be cleaned with
A volatile petroleum-base solvent
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
In the four-digit aluminum index system number 2024, the first digit indicates
The major alloying element
The testing medium that is generally used in magnetic particle inspection utilizes a ferromagnetic material that has
High permeability and low retentivity
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.
What tool is generally used to calibrate a micrometer or check its accuracy?
Gauge block
What type crack can be detected by magnetic particle inspection using either circular or longitudinal magentization?
45 degrees
Why is steel tempered after being hardned?
To relieve its internal stresses and reduce its brittleness
What is generally used in the construction of aircraft exhaust collectors, stacks, and manifolds?
Stainless steel
Which of the following materials may be inspected using the magnetic particle inspection method?
1) Magnesium alloys
2) Aluminum alloys
3) Iron alloys
4) Copper alloys
5) Zinc alloys
3
The clearance between the piston rings and the piston lands is measured with a
thickness gauge
How is the locking feature of the fiber-type locknut obtained?
By the use of an unthreaded fiber locking insert.
In magnetic particle inspection, a flaw that is perpendicular to the magnetic field flux lines generally causes
A large distribution in the magnetic field.
Unless otherwise specified, torque values for tightening aircraft nuts and bolts relate to
Clean dry threads
(Refer to Figure 46.) The measurement reading on the illustrated micrometer is
0.2851
(Refer to Figure 43.) Identify the clevis bolt illustrated
3
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-treat conditions?
Eddy Current Inspection
normalizing is a process of heat-treating
Iron-base metals only.
What is the descriptive of the annealing process of steel during and after it has been annealed?
Slow cooling; low strength
Aircraft bolts are usually manufactured with a
Class 3 fit for the threads
(Refer to Figure 49.) The measurement reading on the micrometer is
0.2792
In performing a dye penetrant inspection, the developer
Acts as a blotter to produce a visible indication.
The reheating of a heat treated metal, such as with a welding torch
Can significantly alter a metal’s properties in the reheated area.
The core material of Alclad 2024-T4 is
Heat-treated aluminum alloy, and the surface material is commercially pure aluminum.
When the specific torque value for nuts is not given, where can the recommended torque value be found?
AC 43.13-1B
Self-locking nuts may be used on aircraft provided that
The bolt or nut are not subject to rotation.
Which of the following methods may be suitable to use to detect cracks to open ti the surface in aluminum forgings and castings?
1) Dye Penetrant Inspection
2) Magnetic particle inspection
3) Metallic ring (coin tap) inspection
4) Eddy Current Inspection
5) Ultrasonic inspection
6) Visual Inspection
1,4,5,6
Which heat0treating process of metal procedures a hard, wear resistant surface over a strong, tough core?
Case hardening
(Refer to Figure 44.) Select the illustration which depicts a cold weld
2
Where is an AN clevis bolt used in an airplane?
Only for shear load applications
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
Change washers and try again
(Refer to Figure 44.) Identify the weld caused by an excessive amount of acetylene
3
If it is necessary to accurately measure the diameter of a hole approximately 1/4 inch in diameter, the mechanic should use a
Small-hole gauge and determine the size of the hole by taking a micrometer reading of the ball end of the gauge.
A bolt with an X inside a triangle on the head is classified as an
NAS close tolerance bolt
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.
Alclad metal consisting of
Pure aluminum surface layers on an aluminum alloy core.
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 magnetized by subjecting it to a magnetizing force from a direct current that is alternately reversed in direction and gradually reduced in strength.
Regarding the above statements,
Both no.1 and no.2 are true
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.
What two types of indicating mediums are available for magnetic particle inspection?
Wet and dry process materials
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
Generally speaking, bolt grip lengths should be
Equal to the thickness of the material which is fastened together
If dye penetrant inspection indications are not sharp and clear, the most probable cause is that the part
Was not thoroughly washed before the developer was applied
The side clearances of piston rings are measured with a
Thickness gauge
The aluminum code number 1100 identifies what type of aluminum?
99 percent commercially pure aluminum
Identify the correct statement
Dividers do not provide a reading when used as a measuring device.
Which tool is used to measure the clearance between a surface plate and a relatively narrow surface being checked for flatness?
Thickness gauge
Which of the nondestructive methods is suitable for the inspection of most metals, plastics, and ceramics for surface and subsurface defects?
Ultrasonic inspection
How many of these factors are considered essential knowledge for x-ray exposure?
1) Processing of the firm
2) Material thickness and density
3) Exposure distance and angle
4) Film characteristics
Three
(Refer to Figure 45.) What type of weld is shown at A?
Butt
What aluminum alloy designations indicate that the metal has received no hardening or tempering treatments?
3003-F
Circular magnetization of a part can be used to detect which defects?
Defects parallel to the long axis of the part.
Which of the following occurs when a mechanical force is repeatedly applied to most metals at room temperature, such as rolling, hammering, or bending?
1) The metals become artificially aged.
2) The metals become stress corrosion cracked.
3) The metals become cold worked, strain or work hardened.
3
Which condition indicates a part has cooled too quickly after being welded?
Cracking adjacent to the weld
(Refer to Figure 42.) Which of the following bolthead code markings shown identifies an AN corrosion resistant steel bolt?
3
Which tool can be used to measure the alignment of a rotor shaft or the plane of rotation of a disk?
Dial indicator
Select a characteristic of a good gas weld.
The weld should taper off smoothly into the base metal
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.
(Refer to Figure 48.) What does the micrometer read?
.3004
Which material cannot be heat treated repeatedly without harmful effects?
Clad aluminum alloy
Which metal has special short-time heat properties and is used in the construction aircraft firewalls?
Titanium alloy
A bolt with a single raised dash on the head is classified as an
AN corrosion-resistant steel bolt
Which tool is used to find the center of a shaft or other cylindrical work?
Combination set
The core material of Alclad 2024-T4 is
Heat-treated aluminum alloy, and the surface material is commercially pure aluminum
Which of the following describe the effects of annealing steal and aluminum alloys?
1) Decrease in internal stress
2) Softening of the metal
3) Improved corrosion resistance
1,2
Under magnetic particle inspection, a part will be identified as having a fatigue crack under which condition?
The discontinuity is found in a highly stress area of the part.
Unless otherwise specified or required, aircraft bolts should be installed so that the bolthead is
Upward, or in a forward direction.
Which statement regarding aircraft bolts is correct?
In general, bolt grip lengths should equal the material thickness.
In performing a dye penetrant inspection, the developer
Acts as a blotter to produce a visible indication
On a fillet weld, the penetration requirement includes what percentage(s) of the base metal thickness?
25 to 50 percent
Liquid penetrant inspection methods may be used on which of the following?
1) Porous plastics
2) Ferrous metals
3) Nonferrous metals
4) Smooth primer sealed wood
5) nonporous plastics
2,3,5
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.
Regarding the above statements,
Both no.1 and no.2 are true
What may be used to check the stem on a poppet-type valve for stretch?
micrometer
One way a part may be demagnetized after magnetic particle inspection is y
Slowly moving the part out of an ac magnetic field of sufficient strength.
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.
What tool is generally used to set a divider to set an exact dimension?
Machinist scale
Which of the following defects are not acceptable for metal lines?
1) Cracked flare
2) Seams
3) Dents in the heel of a bend less than 20% of the diameter
4) Scratches, nicks on the inside of a bend less than 10% of wall thickness
5) Dents in straight section that are 20% of tube diameter
1,2,3, and 5
A mechanic has completed a bonded honeycomb repair using the potted compound repair technique. What nondestructive testing method is used to determine the soundness if the repair after the repair has cured?
Reveal all possible defects
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
1/2 inch
(Refer to Figure 47.) What is the measurement reading on the vernier caliper scale?
1.436 inches
In examining and evaluating a welded joint, a mechanic should be familiar with
Likely ambient exposure conditions and intended use of the part, along with type of weld and original part material composition
Which tool can be used to determine piston pin out-of-round wear?
micrometer caliper
Magnetic particle inspection is used primarily to detect
Flaws on or near the surface
The pattern for an inclusion is a magnetic particle build up forming
Parallel lines
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
thickness gauge
What type of corrosion may attack the grain boundaries of aluminum alloys when the heat treatment process has been improperly accomplished?
Intergranular
What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks and other defects?
Continuous
To detect a minute crack using dye penetrant inspection usually requires
A longer-than-normal penetrating time
Which number represents the vernier scale graduation of a micrometer?
0.0001
identify the weld caused by an excessive amount of acetylene
3
