Practice Exam Questions And Correct

AWS Certified Welder Aluminum D1.2 Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary alloying element in 5XXX series aluminum?

a) Silicon

b) Zinc

c) Magnesium

d) Copper

Rationale: Magnesium is the main alloying element in the 5XXX

series, providing good corrosion resistance and moderate strength.

• Which welding process is most commonly used for aluminum in

structural applications?

a) Shielded Metal Arc Welding (SMAW)

b) Gas Tungsten Arc Welding (GTAW/TIG) 1 / 4

c) Submerged Arc Welding (SAW)

d) Oxy-Acetylene Welding

Rationale: GTAW (TIG) is preferred for aluminum due to its precise

control and clean welds.

• What is the typical preheat temperature for welding 6061 aluminum?
• 200°F (93°C)
• 150°F (65°C)
• 100°F (38°C)

d) No preheat required

Rationale: Aluminum usually requires minimal preheating; 100°F

helps reduce thermal shock without causing distortion.

• Why is AC current used for GTAW aluminum welding?

a) It produces a deeper penetration

b) It reduces oxide formation

c) It cleans the aluminum surface by breaking up oxide layers

d) It is cheaper than DC

Rationale: AC polarity alternates between cleaning action (electrode

positive) and penetration (electrode negative) to manage the oxide layer.

• What is the maximum allowable hydrogen content in aluminum

welding wire?

• 2 ml/100 g
• 1 ml/100 g 2 / 4

• 0.5 ml/100 g
• 3 ml/100 g

Rationale: Hydrogen causes porosity; AWS limits it to 1 ml/100 g to

ensure weld quality.

• Which joint design is preferred for thick aluminum plates?

a) Square groove

b) Double-V groove

c) Bevel groove with backing

d) Fillet weld only

Rationale: Double-V groove helps reduce distortion and allows

complete penetration on thick plates.

• What shielding gas is commonly used for GTAW of aluminum?

a) CO2

b) Argon-Helium mix

c) Pure Argon

d) Nitrogen

Rationale: Argon provides a stable arc and protects aluminum from

oxidation.

8. Aluminum exhibits a tendency to:

a) Crack less than steel

b) Harden rapidly

c) Oxidize rapidly

d) Retain heat longer 3 / 4

Rationale: Aluminum forms a tough oxide layer that melts at higher

temperatures, which can affect weld penetration.

• Which of the following can cause porosity in aluminum welds?

a) Excessive heat

b) Low travel speed

c) Moisture or contaminants

d) Correct shielding gas

Rationale: Moisture or surface contamination introduces hydrogen,

leading to porosity.

• How should aluminum surfaces be prepared before welding?

a) Wire brush with steel

b) Sand with steel wool

c) Clean with stainless steel brush or chemical cleaner

d) Wipe with oily rag

Rationale: Steel contamination can cause weld defects; only stainless

steel brushes or suitable chemical cleaners are recommended.

• What is the recommended filler metal for welding 5XXX series

aluminum?

• 4045
• 5356
• 5356 or 5183
• 6061
• / 4