A&P - Airframe

In Gas Tungsten Arc (GTA) welding, a stream of inert gas is used to. prevent the formation of oxides in the puddle. concentrate the heat of the arc and prevent its dissipation. lower the temperature required to properly fuse the metal.

Which statement best describes magnesium welding?. Magnesium can be welded to other metals. Filler rod should be nickel-steel. Filler rod should be the same composition as base metal.

Which statement is true in regard to welding heat-treated magnesium?. The welded section does not have the strength of the original metal. Flux should not be used because it is very difficult to remove and is likely to cause corrosion. Magnesium cannot be repaired by fusion welding because of the high probability of igniting the metal.

The oxyacetylene flame for silver soldering should be. oxidizing. neutral. carburizing.

Why is it necessary to use flux in all silver soldering operations?. To chemically clean the base metal of oxide film. To prevent overheating of the base metal. To increase heat conductivity.

Engine mount members should preferably be repaired by using a. larger diameter tube with fishmouth and no rosette welds. larger diameter tube with fishmouth and rosette welds. smaller diameter tube with fishmouth and rosette welds.

What method of repair is recommended for a steel tube longeron dented at a cluster?. Welded split sleeve. Welded outer sleeve. Welded patch plate.

Welding over brazed or soldered joints is. not permitted. permissible for mild steel. permissible for most metals or alloys that are not heat treated.

Which statement concerning soldering is correct?. Joints in electric wire to be soldered should be mechanically secure prior to soldering. Changeable shades of blue can be observed on the surface of a copper soldering tip when the proper temperature for soldering has been reached. If the soldering temperature is too high, the solder will form in lumps and not produce a positive bond.

A resurfaced soldering iron cannot be used effectively until after the working face has been. fluxed. polished. tinned.

Which of the following can normally be welded without adversely affecting strength? 1. Aircraft bolts. 2. SAE 4130 chrome/molybdenum tubing. 3. Spring steel struts. 4. Most heat-treated steel/nickel alloy components. 2 and 4. 1 and 3. 2.

In selecting a torch tip size to use in welding, the size of the tip opening determines the. amount of heat applied to the work. temperature of the flame. melting point of the filler metal.

Why should a carburizing flame be avoided when welding steel?. It removes the carbon content. It hardens the surface. A cold weld will result.

The most important consideration(s) when selecting welding rod is. current setting or flame temperature. material compatibility. ambient conditions.

The oxyacetylene flame used for aluminum welding should. be neutral and soft. be slightly oxidizing. contain an excess of acetylene and leave the tip at a relatively low speed.

A very thin and pointed tip on a soldering copper is undesirable because it will. transfer too much heat to the work. have a tendency to overheat and become brittle. cool too rapidly.

Filing or grinding a weld bead is considered to be. an acceptable means to achieve a smoother surface. a way to bring about strength reduction in joint. frequently necessary to avoid adding excess weight to a weld joint.

Acetylene at a line pressure above 15 PSI is. dangerously unstable. used when a reducing flame is necessary. usually necessary when welding metal over 3/8-inch thick.

Cylinders used to transport and store acetylene. are pressure tested to 3,000 PSI. are green in color. contain acetone.

A welding torch backfire may be caused by. a loose tip. using too much acetylene. a tip temperature that is too cool.

Which statement concerning a welding process is true?. The inert-arc welding process uses an inert gas to protect the weld zone from the atmosphere. In the metallic-arc welding process, filler material, if needed, is provided by a separate metal rod of the proper material held in the arc. In the oxyacetylene welding process, the filler rod used for steel is covered with a thin coating of flux.

Where should the flux be applied when oxyacetylene welding aluminum?. Painted only on the surface to be welded. Painted on the surface to be welded and applied to the welding rod. Applied only to the welding rod.

What purpose does flux serve in welding aluminum?. Removes dirt, grease, and oil. Minimizes or prevents oxidation. Ensures proper distribution of the filler rod.

Why are aluminum plates 1/4 inch or more thick usually preheated before welding?. Reduces internal stresses and assures more complete penetration. Reduces welding time. Prevents corrosion and ensures proper distribution of flux.

How should a welding torch flame be adjusted to weld stainless steel?. Slightly carburizing. Slightly oxidizing. Neutral.

Oxides form very rapidly when alloys or metals are hot. It is important, therefore, when welding aluminum to use a. solvent. filler. flux.

In gas welding, the amount of heat applied to the material being welded is controlled by the. oxygen-acetylene regulator. size of the tip opening. cutting oxygen valve lever.

Oxygen and acetylene cylinders are made of. seamless aluminum. steel. bronze.

When a butt welded joint is visually inspected for penetration,. 50 percent of the thickness of the base metal. 100 percent of the thickness of the base metal. 75 percent of the thickness of the base metal.

Annealing of aluminum. increases the tensile strength. makes the material brittle. removes stresses caused by forming.

Edge notching is generally recommended in butt welding above a certain thickness of aluminum because it. helps hold the metal in alignment during welding. aids in the removal or penetration of oxides on the metal surface. aids in getting full penetration of the metal and prevents local distortion.

If too much acetylene is used in the welding of stainless steel,. a porous weld will result. the metal will absorb carbon and lose its resistance to corrosion. oxide will be formed on the base metal close to the weld.

The shielding gases generally used in the Gas Tungsten Arc (GTA) welding of aluminum consist of. a mixture of nitrogen and carbon dioxide. nitrogen or hydrogen, or a mixture of nitrogen and hydrogen. helium or argon, or a mixture of helium and argon.

High pressure cylinders used to transport and store acetylene must. be pressure tested to 3,000 PSI. be green in color. contain acetone.

Which statement best describes magnesium welding?. It has low thermal conductivity, so distortion and cracking rarely occur. It is recommended to use larger welding beads and a slower welding speed than normal. It can be welded successfully using the same type of joints that are used for aluminum.

When welding or cutting, the acetylene pressure gauge should never be set higher than. 15 PSI. 20 PSI. 25 PSI.

When selecting a welding rod, one of the most important factors to consider is to ensure that. ferrous rods are used on aluminum. the proper AMS specification number is used. nonferrous rods are used on steel.