GSI Group - Laser Division
JK300HP/JK300P/JK125P
Pre-installation and User Manual
Issue 2.0
Page 164 of 172
Part No: 1EA300E01
10.8 Material Welding
Laser welding is a highly controllable fusion welding process. This process can be used to
weld all metallic materials that are weldable using conventional welding processes.
Materials welded using high power Lasers are as follows:
Material Information
Zinc-coated automotive
steel
Generally weldable with coating thickness up to 15
µ
m/side if a joint gap
is introduced to allow vaporising zinc to escape.
Carbon and Carbon-
Manganese steels
Readily weldable up to 3mm without gas shield and in greater thickness
with gas shield. May encounter cracking in steels with high Carbon
content.
Stainless steel and Nickel-
based alloys
Readily weldable with good gas shield. Cleaning and degreasing prior
to welding often necessary.
Titanium and Titanium
alloys
Readily weldable but requires excellent gas shielding
Aluminium and Aluminium
alloys
Pure and lean alloys are readily weldable with good gas shielding. 5000
and 6000 series alloys may require filler wire in addition to overcome
cracking.
Copper and Copper alloys
Generally weldable although combination of high reflectivity and
thermal conductivity can cause problems. Bismuth- and alloys
containing Lead can crack.
Some of the benefits of Laser welding such as high welding speed and minimum workpiece
distortion, are maximised when the Laser is used to make autogenous welds (i.e. with no
material addition in the form of filler wire, powder, shim etc.). However, some materials
require material addition to give high quality welds with acceptable properties.
At the high power level of the JK300HP/JK300P/125P Series Laser, welding with material
addition is readily achievable although welding speeds are generally lower than with
autogenous welding.
Some highly reflective materials can be difficult to weld because the majority of the Laser
beam is reflected from the material surface preventing heating and melting. This is the case
with Gold, Silver, their alloys and with some Copper alloys.
With all materials, it is important that surfaces to be welded are free of oxidation, oil, grease,
cutting fluid etc. Contamination of this kind is likely to result in porosity and other defects in
the weld. Appropriate cleaning procedures must be applied to remove contamination from
surfaces to be welded.
10.9 Cutting in CW Mode
Focusing the Laser beam onto the surface of the material to be cut at an intensity sufficient
to ensure material heating, melting and vaporisation achieves cutting. A co-axial assist gas
is applied through the cutting nozzle that directs the gas at the beam/material interaction
point. , A continuous cut can be produced along a predetermined path by moving the
workpiece relative to the Laser beam.
The assist gas facilitates removal of molten material from the cut. In a given material, the
Laser Average Power, the cutting speed and the type of gas used control the thickness of
material that can be cut. The width of cut is controlled by the focused spot size.
Increased power (with other parameters constant) increases the thickness of material that
can be cut.
Increased Laser power decreases cutting speed.
Petitioners Canadian Solar Inc. and Canadian Solar (USA) Inc.
Ex. 1025, p. 164
