GMAW on Aluminum Flashcards
Up to what length of contact tip is best suited for GMAW with aluminum filler wires?
a) 25.4 mm (1”)
b) 50.8 mm (2”)
c) 76.2 mm (3”)
d) 101.6 mm (4”)
d) 101.6 mm (4”)
List three (3) advantages of using GMAW on aluminum.
a)
b)
c)
Any three (3) of the following are correct.
a) high deposition rates compared to GTAW
b) can be used long distances from the power source
c) no flux or slag; no inclusions in the weld metal
d) clean up time is reduced or eliminated
e) may be used in all positions
f) works well on materials 3.2 mm (1/8”) and up
g) works well for spot welding operations
Which aluminum filler metal is not recommended for sustained high temperature service?
a) 2319
b) 4145
c) 4043
d) 5356
d) 5356
What three (3) factors should you consider when setting GMAW welding parameters?
a)
b)
c)
a) material thickness
b) alloy type
c) available equipment
What effect does stickout have on arc length with GMAW on aluminum?
Due to the high electrical conductivity of aluminum, the electrical stickout is not as critical as that required for steel. The resistance of the aluminum wire is almost the same for a long stickout as it is for a short stickout. Very little change in arc length is noticed with various stickout distances.
After pre-cleaning aluminum, you should weld the joint:
a) with a copper backing bar to prevent oxide contamination.
b) before it dries to prevent cracking.
c) after age hardening has occurred.
d) as soon as all liquids have evaporated from the joint area.
d) as soon as all liquids have evaporated from the joint area.
What precaution must you take when using heavy wire brushing or an abrasive grinding disc to remove a heavy oxide layer from aluminum?
Heavy brushing or abrasive discs tend to drive the aluminum oxides into the metal surface and entrap them. The result is possible contamination of the weld.
What are the two most commonly used filler metals for GMAW on aluminum?
a) 2319 and 4145
b) 4145 and 5356
c) 4043 and 4047
d) 4043 and 5356
d) 4043 and 5356
What is the purpose of a light preheat on aluminum alloys?
a) to remove moisture
b) to reduce residual stresses after welding
c) easier arc starting
d) to remove surface oxides
a) to remove moisture
What type of current do you use with GMAW for welding aluminum?
a) AC
b) DCEP
c) DCEN
d) AC with continuous high frequency
b) DCEP
What methods can you use to fill a crater?
A common method of filling the crater is to reverse travel direction for a short distance. Other techniques may use run-off tabs, breaking and restarting the arc or the use of special current controls on the power source.
What electrode inclination is recommended for the welding of aluminum?
forehand at all times
Most shielding gases for GMAW on aluminum are:
a) inert gases.
b) oxidizing gases.
c) nitriding gases.
d) ionized gases.
a) inert gases.
The shielding gas most commonly used with GMAW on non-ferrous metals is:
a) carbon dioxide.
b) nitrogen.
c) helium.
d) argon.
d) argon.
- List four (4) causes of burnback.
a)
b)
c)
d)
Any four (4) of the following are correct.
a) wire feed speed too slow
b) worn or dirty contact tube
c) worn or dirty liner
d) wrong polarity
e) kinked electrode wire
f) liner too long
g) arcing inside the contact tube
