non-arc welding processes resistive heating, chemical reactions, focused light and electrons, sound...
TRANSCRIPT
Non-Arc Welding Processes• Resistive heating, chemical reactions, focused
light and electrons, sound waves, and friction can also be used to join materials– Resistance welding – Oxy-Fuel Welding– Friction welding (&Solid State)– Laser and electron beam welding– Brazing and soldering– Plastics joining– Adhesive bonding
Introduction
High Energy Density Processes• Focus energy onto
a small area
• Laser– CO2 gas: fixed
position– Nd-YAG crystal:
fiber-optic delivery
• Electron Beam
High Energy Density Processes
High Energy Density Processes• These processes focus the energy onto a
small area
Examples
• Laser - 0.004 inch weld on 1-inch thick stainless steel sheet
• Electron Beam - 0.030-inch weld width on 0.5 inch thick steel plate
0.1.1.2.1.T2.95.12
Laser Beam Welding (LBW)
0.1.1.2.1.T3.95.12Laser
Laser Beam Welding (LBW)
Keyhole welding
Laser beam
Plasma plume
Moltenmaterial
shieldinggas nozzle(optional)
workpiece motion
Plasmakeyhole
High Energy Density Processes
Focusing the Beam
Heat Surface Welding Cuttingtreatment modification
High Energy Density Processes
Advantages• Single pass weld
penetration up to 3/4” in steel
• High Travel speed• Materials need not be
conductive• No filler metal
required• Low heat input
produces low distortion
• Does not require a vacuum
0.1.1.2.1.T4.95.12
0
2
4
6
8
10
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1 3 5 7Welding speed, m/min
Wel
d p
enet
rati
on
, m
m
6 kW CO2
2 kW Nd:YAG
Limitations
• High initial start-up costs • Part fit-up and joint tracking are
critical• Not portable• Metals such as copper and
aluminum have high reflectivity and are difficult to laser weld
• High cooling rates may lead to materials problems
High Energy Density Processes
Electron Beam Welding (EBW)
• Deepest single pass weld penetration of the fusion processes– 14-inch-thick steel
• Fast travel speeds• Low heat input welds
produce low distortion
High Energy Density Processes
Advantages
Limitations• High initial start-up cost
• Not portable
• Part size limited by size of vacuum chamber
• Produces x-rays
• Part fit-up is critical
• High cooling rates may lead to materials problems
High Energy Density Processes