Lasers – Efficiency and Strength for Lightweighting Laser Processing of Steel

F150 Roof Welding Process

? Laser Joining
? Laser Welding
? Laser Welding with Filler Wire
? Remote Laser Welding
? Laser Brazing
? Laser Hardening
? Laser Softening
? Laser Surface Treatment
? Laser Drilling

Basic Principle
? Laser beam provides a highly concentrated heat source
? Melts metal and even produces vapor (plasma)
? As the laser beam moves along the joint, weld is created upon solidification

? Body in White
? Tubes and Closures
? Powertrain
? Tailor Welded Blanks
? Eliminates bolted assembly for weight
reduction and material cost saving!
? Less assembly steps, remove the need
for machining holes and bolting
assembly!
? Minimal heat input and distortion
? Proven performance and durability

 Weld defects due to
? alloy metallurgical incompatibility
? dissimilar material
? Weld geometry not meeting specifications
Laser Welding with filler wire
? Welded surface not aesthetically smooth
? High power melts the zinc coating
Laser Brazing
? No fast movement between the welds
Laser Remote Welding

Basic Principle
? During laser welding, external wire is fed into the
melt pool
? As the laser beam and wire moves along the joint,
the weld is created upon solidification
? Filler material
? Metal cold/hot wire
Applicability
? Otherwise not laser weldable materials
? Overcome poor weld geometry or fit up
? Change weld chemistry and properties

? Welding of Dissimilar Materials
Steel 4320 – Steel 8620
using Ni-based filler wire
? Laser welding can weld
conventionally un-weldable
materials such as higher carbon
steels and cast irons using filler wire
or pre heat techniques

? Laser Joining
? Laser Welding
? Laser Welding with Filler Wire
? Remote Laser Welding
? Laser Brazing
? Laser Hardening
? Laser Softening
? Laser Surface Treatment
? Laser Drilling

Basic Principle
? Uses a relatively long focusing optic (hence "remote")
? Highly dynamic scanning mirrors enable extremely fast indexing
in-between welds
? Therefore laser is spending more time joining parts and much
less time waiting
Applicability
? Fast and Flexible
? No limitation of weld geometry and speed

Reduction of flange width
? Additional potential for mass reduction
? High beam - to - seam accuracy is required 
? Seam tracking with remote welding head can be utilized

Has been Implemented by:
? BMW (various models inc Liftgate)
? Chrysler Sebring (Liftgate)
? Ford (Mondeo – Roof development)
? GM – Cadillac CTS (Roof and Liftgate)
? Mercedes (Liftgate)
? VW / Audi / SEAT (various)
? Renault (Roof)

? Turn-key integrated laser in-process monitoring
system for laser welding
? High speed camera with illumination
? Robust industrial system can be integrated in
existing laser welding setup
? Defect detection operator feedback (OK/NOK)

Basic Principle
? Laser beam heats the surface just below the melting point
? Very high cooling rate is obtained by moving the beam
? High hardness is achieved

Basic Principle
? Laser beam heats steel sheet above transition
temperature
? By moving the beam, a larger area is treated
and cooling rate is controlled
? Suitable microstructures are formed by
rearrangement and softening is achieved
Applications
? Selective softening for easier formability or
mechanical fastening
? High speed process compared to
conventional heat treatments
? Tailored microstructures

? Laser applications employed by automotive industry for steel
? Welding
? Hardening
? Surface treatment
? Drilling
? The automotive industry has incorporated laser processing in virtually every sub-system of
the automobile
? Ongoing laser innovations will continue to make laser implementation more and more
affordable
? Lasers are a key technology enabler for mass reduction in steel vehicles!