ACRM-WELDING

Question 1

Blending of compatible molten metals into one common part or joint.

Answer 1

FUSION

Question 2

Joining of metals by adhesion of one metal to another

Answer 2

NON-FUSION

Question 3

Primary concern to a welder. Metal oxides are formed in the welding zone of most metallic alloys when sufficient heat is applied. Oxygen chemically reacts with the heated surface of the metal and forms metal oxides such as iron oxide or aluminum oxide.

Answer 3

OXIDATION

Question 4

Oxygen and acetylene, that are used to produce a flame. Acetylene is the fuel for the flame and oxygen supports combustion and makes the flame hotter. Temperature of the oxyacetylene welding ranges from 5600F to 6300F.

Answer 4

OXYACERELENE WELDING

Question 5

Predominantly used in aircraft fabrication and repair.

Answer 5

ELECTRIC ARC WELDING

Question 6

Stick welding is the most common type of arc welding. Composed of approximately the same chemical composition as the metal to be welded, is clamped in an electrode holder.
Capable of exceeding 10,000F

Answer 6

SHIELDED METAL ARC WELDING (SMAW)

Question 7

Used primarily in large volume production work. No slag is deposited on the weld bead. An uncoated filler wire acts as the electrode.
An inert gas such as argon, helium or carbon dioxide flows out around the wire to protect the weld zone from oxygen.

Answer 7

GAS METAL ARC WELDING (GMAW)

Question 8

Used in most aircraft maintenance. TIG welding uses a tungsten electrode that does not act as filler rod. The arc is concentrated on a small area of the metal, raising its temperature to as high as 11,000F.

Answer 8

TUNGSTEN INERT GAS WELDING (TIG)

Question 9

Many thin sheet metal parts for aircraft, especially stainless steel parts, are joined by one of the forms of ______ ________ __________.

Answer 9

ELECTRIC RESISTANCE WELDING

Question 10

Two copper electrodes are held in the jaws of a vise-like machine and the pieces of metal to be welded are clamped between them. Pressure is applied to hold the electrodes tightly together while electrical current passes between the electrodes. The duration that the electric current flows is referred to as the dwell time.

Answer 10

SPOT WELDING

Question 11

Commonly used to manufacture fuel tanks and other components where a continuous weld is needed. The metal in a seam welder is drawn between two coppers. Pressure is applied to the wheels and timed pulses of current flow through the metal between them.

Answer 11

SEAM WELDING

Question 12

TYPES OF WELDED JOINTS

Answer 12

BUTT, EDGE LAP, CORNER, TEE

Question 13

Metal that is deposited as the weld is made

Answer 13

BEAD

Question 14

Exposed surface of the weld

Answer 14

FACE

Question 15

Depth that fusion penetrates into the base metal

Answer 15

ROOT

Question 16

Distance through the center from the root to the face

Answer 16

THROAT

Question 17

Edge formed where the face of the weld meets the base metal

Answer 17

TOE

Question 18

Quantity of weld metal added above the surface of the base metal

Answer 18

REINFORCEMENT

Question 19

Form of metal joining in which an iron-free metal is used as a cohesive material, usually brass or bronze, is melted with an oxyacetylene torch at a temperature above 800F

Answer 19

TORCH BLAZING

Question 20

is used to clean the surface of the metal being joined. A ______ coating on a filler rod allows it to flow when melted and to adhere to a base metal surface.

Answer 20

FLUX

Question 21

Normally melt at temperatures lower than 800F.

Answer 21

TORCH SOLDERING

Question 21

A technician may need to solder joints in an air-conditioning system
Made with a close fit between the parts. The joint is fluxed and uniformly heated with a soft flame.
Primarily a mixture of tin and lead

Answer 21

SOFT SOLDERING

Question 22

The filler material melts at a temperature more than 800F. The oxyacetylene flame for silver soldering should be neutral, but may have a slight excess of acetylene. The flame must be soft.
To conform to commonly accepted terminology in aircraft maintenance, silver brazing will be called silver soldering.
Stainless steel oxygen lines often have their end fittings attached by silver soldering.

Answer 22

HARD SOLDERING

Question 23

Difficult to weld since the color does not change as it nears the melting temperature.
Done with gas-shielded electric arc, sometimes either acetylene or hydrogen gas. Hydrogen is preferred due to cleaner flame and less risk of oxidizing. For an equal thickness of metal, hydrogen requires a larger tip.
Flame should be neutral or slightly carburizing.

Answer 23

GAS WELDING

Question 24

Preferred method. The heat from the TIG torch is much more concentrated that is it with an oxygen torch.
It should be brushed with a hog bristle or stainless steel brush to remove the oxide film, then scrubbed with solvent.

Answer 24

TIG WELDING

Question 25

Use more oxygen. The cut made by an oxyacetylene cutting torch is known as a kerf.

Answer 25

OXYACETELENE CUTTING