Chapter 4 Section B (Unit 3)

4-14. AMA101

Which statement best describes magnesium welding?

A. Filler rod should be nickel steel.

B. Magnesium can be welded to other metals.

C. Filler rod should be the same composition as base metal.

Answer C. JSAT 4B, FAH

For the strength of the weld to match the strength of the base metal, alloy of the filler rod should be of the same composition as the base metal.

4-15. AMA058

Which statement is true in regard to welding heat-treated magnesium?

A. Magnesium cannot be repaired by fusion welding because of the high probability of igniting the metal.

B. Flux should not be used because it is very difficult to remove and is likely to cause corrosion.

C. The welded section does not have the strength of the original metal.

Answer C. AC 43.13-1B, FAH

Repair of magnesium by welding is limited by the fact that it is used as a structural member, it has probably been heat treated. As is true with heat treated aluminum, welding heat treated magnesium does not leave as much strength as the original metal had.

4-16. AMA101

Engine mount members should preferably be repaired by using a

A. smaller diameter tube with fishmouth and rosette welds.

B. larger diameter tube with fishmouth and no rosette welds.

C. larger diameter tube with fishmouth and rosette welds.

Answer C. AC 43.13-1B, FAH

All welding on engine mount should be of the highest quality, since vibration tends to accentuate any minor defect. Engine mount members should preferably be repaired by using a larger diameter replacement tube telescoped over the stub of the original member, using fishmouth and rosette welds.

4-17. AMA101

What method of repair is recommended for a steel tube longeron dented at a cluster?

A. Welded patch plate.

B. Welded split sleeve.

C. Welded outer sleeve.

Answer A. JSAT 4B, AC 43.13-1B

A dent at a cluster should be repaired by welding a specially formed steel patch plate over the dented area and surrounding tubes.

4-18. AMA101

The oxyacetylene flame used for aluminum welding should

A. be neutral and soft.

B. contain an excess of acetylene and leave the tip at relatively low speed.

C. be slightly oxidizing.

Answer A. JSAT 4B

The flame used for welding aluminum should be soft and neutral or slightly carburizing, to be sure that there will be no possibility of the metal being oxidized from the welding.