Aircraft Mechanical Process Flashcards
(41 cards)
The occurrence of shallows, spherical depressions in a surface, usually produced by a part
having a small radius in contact with the surface under high load
Brinelling
The Polishing of one surface by sliding contact with a smooth, harder surface and usually
no displacement nor removal of metal
Burnishing
A small, thin section of metal extending beyond a regular surface, usually located at a corner or
on the edge of a bore or hole
Burr
The Loss of metal from the surface by chemical or electrochemical action, this corrosion
products generally are easily removed by mechanical means andiron rust is an example of corrosion
Corrosion
It is a physical separation of two adjacent portions of metal evidence by a fine or thin line across
the surface caused by excessive stress at that point. It may extend inward from the surface from
thousandths inch to completely through the section thickness
Crack
A loss of metal, usually to an appreciable depth over a relatively long and narrow area, by
mechanical means, as would occur with the use of a saw blade, chisel or sharp- edged stone striking a
glancing blow
Cut
It is the indentation in a metal surface produced by an object striking with force. The surface
surrounding the indentation will usually be slightly upset
Dent
It is the loss of metal from the surface by mechanical action of foreign objects, such as grit or
fine sand. The eroded area will be rough and may be lined in the direction in which the foreign material
moved relative to the surface
Erosion
It is the breakdown or deterioration of metal surface by vibratory or “chattering” action and
usually no loss of metal or cracking of surface but generally showing similar appearance
Chattering
It is the breakdown or build-up of metal surfaces due to excessive friction between two parts
having relative motion. Particles of the softer metal are torn loose and “welded” to the harder
Galling
The grooves in, or breakdown of, a metal surface from contact with foreign material under
heavy pressure. Usually indicates metal loss but may be largely displacement of material
Gouge
Is the presence of foreign or extraneous material wholly within a portion of metal in which
such material is introduced during the manufacture of rod, bar or tubing by rolling or forging
Inclusion
Local break or notch on edge, usually displacement of metal rather than loss
Nick
Is the sharp localized breakdown of small or deep cavity of metal surface, usually with defined
edge
Pitting
It is the slight ear or break in metal surface from light, momentary contact by foreign material
Scratch
It is deeper than scratch, tear or break in metal surface from contact under pressure and may
show discoloration from temperature produced by friction
Score
It is a change in color locally causing a noticeably different appearance from the surrounding
area
Stain
It is a displacement of material beyond the normal contour or surface (a local bulge or
bump), usually indicates no metal loss.
Upsetting
The Vital Characteristics to Construct the Structural Metals for Airframes are:
a. Knowledge on the Uses of Materials
b. Understanding the Uses of Materials
c. Material Strengths
d. Material Limitation
It is the damage which does not affect the structural integrity of the member
involved or damage which can be corrected by a simple procedure without placing flight restriction on
the aircraft is classified as negligible damage. Small dents, scratches, cracks, or holes that can be
repaired by smoothing, sanding stop drilling, or hammering out or otherwise repaired without the use of
additional materials, fall in this classification.
Negligible Damage.
Is any damage exceeding negligible damage limits which can be repaired by bridging the damage area of a component with a material splices. The splice or patch
materials used in internal riveted and bolted repairs is normally the same type of materials as the
damaged parts, but one gage heavier. In a patch repair, filler plates of the same gage and type of
materials as that in the damaged components may be used for bearing purposes or to return the
damaged part to its original contour.
Damage Repairable by Patching
It is the damage which can be repaired by cutting away the damaged section and replacing it with a like section, then securing the insertion with splice at each end is
classified as damage repairable by insertion.
Damage Repairable by Insertion
Replacement of an entire part is considered when one or more of the following conditions exist:
-When a complicated part has been extensively damaged
-When surrounding structure makes repair impractical
-When damaged part is relatively easy to replace
-When forged or cast fittings are damaged beyond negligible limits
Damage Necessitating Replacement of Parts.
Sheet metal is often formed or finished over variously shaped anvils called _________. These are used in forming small, odd-shaped parts, or for putting on finishing touches for
which a large machine may not be suited. Dollies are meant to be held in the hand, whereas stakes are
designed to be supported by a flat cast iron bench plate fastened to the work bench. Most stakes have
machined, polished surface which have been hardened. Do not use stakes to back up material when
chiseling, or when using any similar cutting tool because this will deface the surface of the stake and
make it useless for finish work.
Dollies and Stakes
