Joining Process

Question 1

What is joining?

Answer 1

Making parts permanent by welding, brazing, soldering, or adhesives.

Question 2

What is welding?

Answer 2

Coalescing parts by applying heat and/or pressure.

Question 3

What are the two main welding types?

Answer 3

Fusion welding and solid‑state welding.

Question 4

What is fusion welding?

Answer 4

Joining where base metals melt at the joint.

Question 5

What is solid‑state welding?

Answer 5

Joining without melting base metals using pressure and heat.

Question 6

Name a feature of solid‑state welding.

Answer 6

No melting → no heat‑affected zone (HAZ).

Question 7

Give two benefits of solid‑state welding.

Answer 7

Full interface bonding; can join dissimilar metals.

Question 8

What does FOW stand for?

Answer 8

Forge welding.

Question 9

What does CW stand for?

Answer 9

Cold welding.

Question 10

What does DFW stand for?

Answer 10

Diffusion welding.

Question 11

What does EXW stand for?

Answer 11

Explosion welding.

Question 12

What does USW stand for?

Answer 12

Ultrasonic welding.

Question 13

What does FRW stand for?

Answer 13

Friction welding.

Question 14

What does FSW stand for?

Answer 14

Friction stir welding.

Question 15

How does forge welding join metals?

Answer 15

Heat to plastic range and hammer or forge them together.

Question 16

How does cold welding work?

Answer 16

High pressure at room temperature on exceptionally clean surfaces.

Question 17

What is required for cold welding to succeed?

Answer 17

Very clean surfaces and a ductile metal.

Question 18

How does diffusion welding join parts?

Answer 18

Heat + low pressure cause atomic diffusion across the interface.

Question 19

Why is diffusion welding done below melting point?

Answer 19

To avoid melting while enabling atomic migration.

Question 20

How does explosion welding bond plates?

Answer 20

High‑speed collision from an explosive forces surfaces together, expelling gases.

Question 21

What is a main advantage of explosion welding?

Answer 21

Bonds large areas or dissimilar metals quickly without filler.

Question 22

How does friction welding create heat?

Answer 22

Mechanical rubbing (rotation) between parts under pressure.

Question 23

Why trim the flash after friction welding?

Answer 23

Flash is excess material; trimming smooths the weld area.

Question 24

Name an advantage of friction welding.

Answer 24

Narrow HAZ and ability to join dissimilar metals.

Question 25

How does friction stir welding differ from friction welding?

Answer 25

A rotating tool stirs plasticized material; parts do not rotate.

Question 26

What does the tool shoulder do in FSW?

Answer 26

Constrains plasticized metal and controls heat flow.

Question 27

List two benefits of FSW.

Answer 27

Good weld strength and low distortion.

Question 28

What frequency range is typical for ultrasonic welding?

Answer 28

15–75 kHz.

Question 29

What does ultrasonic welding use to join surfaces?

Answer 29

Oscillatory shear vibrations under modest clamp pressure.

Question 30

Where is ultrasonic welding commonly used?

Answer 30

Wire terminations, splicing, and small electronics assemblies.

Question 31

What is brazing?

Answer 31

Filling joint with a molten filler metal that wets parts by capillary action.

Question 32

Does brazing melt the base metals?

Answer 32

No — only the filler metal melts.

Question 33

What is the minimum melting temperature for brazing filler?

Answer 33

Above 450°C.

Question 34

Why is joint clearance important in brazing?

Answer 34

It enables capillary flow; typical 0.025–0.25 mm.

Question 35

What is the purpose of a brazing flux?

Answer 35

Prevent oxide formation and improve wetting.

Question 36

Name three common brazing heating methods.

Answer 36

Torch, furnace, and induction brazing.

Question 37

Give one advantage of brazing.

Answer 37

Joins dissimilar or thin parts with less heat than welding.

Question 38

Give one disadvantage of brazing.

Answer 38

Joint strength is lower than welded joints.

Question 39

What is soldering?

Answer 39

Joining using a filler metal with melting point ≤450°C.

Question 40

Where is soldering mainly used?

Answer 40

Electronic assemblies and low‑stress joints.

Question 41

What is hand soldering?

Answer 41

Using a heated iron to melt solder and form the joint.

Question 42

What is wave soldering?

Answer 42

Mechanized PCB soldering using a wave of molten solder.

Question 43

Give one advantage of soldering.

Answer 43

Low energy input and easy rework.

Question 44

Give one disadvantage of soldering.

Answer 44

Low joint strength and poor high‑temperature performance.

Question 45

What is adhesive bonding?

Answer 45

Using an adhesive to attach parts over their contact surface.

Question 46

What are the main steps in adhesive bonding?

Answer 46

Surface prep, adhesive application, and curing.

Question 47

Name three adhesive categories.

Answer 47

Natural, inorganic, synthetic (thermoplastic/thermosetting).

Question 48

What are advantages of adhesive bonding?

Answer 48

Bonds varied materials, seals joints, and distributes stress.

Question 49

What are limits of adhesive bonding?

Answer 49

Lower strength, limited temperature, and inspection difficulty.

Question 50

How do brazing, soldering, and welding differ regarding base metal melting?

Answer 50

Welding melts base metals; brazing/soldering do not.