Maintenance Practices M7.15A Flashcards
What is capillary action
The process in which the solder flows between 2 surfaces
What is high temp solder
Tin Antimony lead solder
Up to what % antimony increases solder strength
6%
What is the most common non corrosive flux
Rosin
Sulphur embrittlement
Cannot restore
What is the cylinder colour for acetalyne
Maroon
What is pure acetalyne dissolved in
Acetone and pressurised to 15 bar
Why are acetalyne bottles kept upright
Because acetalyne is very unstable
What pressure must acetalyne not exceed when being used as a fuel
15 psi
At what pressure will acetalyne explode
29.4psi
Check valves on acetalyne bottles are only to prevent return of flow what is used as a flashback arrestor
Flashback arrestors
What are the two different types of oxy acetalyne torches
- Equal pressure
- Injector type
Why is equal pressure Better than the injector type
More stable and safe. Less susceptible to flashback
What is fusion welding
Electrically bonding 2 pieces together
What is a class A fusion weld
A vital joint (Failure would jeopardise the aircraft safety)
What is a Class B1 Fusion weld
A secondary structure (Failure would not jeopardise the aircraft safety)
What is a Class B2 fusion weld
Non structural
Is the TIG electrode consumed or not consumed during the welding process
Not consumed
What does TIG stand for
Tungsten Inert Gas
What gas does TIG use
Argon
Why do you not need to use a flux with TIG welding
Argon gas is used which is an inert gas
What current can be used with TIG welding
AC or DC current
The gas metal arc and gas tungsten arc welding processes are known as what
Gas shielded arc process
Which welding process electrode doubles as the weld feed and is consumed
MIG
During the MIG process what helps stop the surface from oxidising
Inert gas and shielding process
How to inspect a weld to see if it’s of good quality
- Visual check
- Uniform in width
- No burn marks
- No oxide present
What is Porosity
When gas is trapped in a weld
What is the best way to detect porosity in a weld
X ray
What is used during the brazing process
Bonding 2 pieces of metal with zinc/copper alloy filler
Is brazing high temp or low temp
Low temp
What adhesive relies on atmosphere
Contact adhesive
What does bonding rely on to be strong and of good quality
Adhesion and cohesion
Which must be stronger adhesion or cohesion
Adhesion
What is wetting
Making sure there is a good surface for bonding
What is capillary action
When two materials are together the binding agent will fill the narrow gaps to perform the bond
Bond line thickness must not be greater than what
0.1mm
