GSI Group - Laser Division
JK300HP/JK300P/JK125P
Issue 2.0
Pre-installation and User Manual
Part No: 1EA300E01
Page
161 of 172
Figure 35 shows the relationship between the welding speed and the frequency for three
different percent overlaps.
Figure 35 – Welding speed vs repetition rate for different percent overlaps (spot size
0.60mm)
In general the higher the peak power the greater the penetration up to limit where the
intensity on the surface causes material to be ejected. At these levels, the process is starting
to drill.
10.3 Welding in Continuous Wave Mode
Welding is achieved by focusing the Laser beam onto the material surface at an intensity
sufficient to effect material heating, melting and vaporisation.
By moving the workpiece relative to the Laser beam, a continuous weld can be produced
along a pre-determined path.
In a given material, the geometric characteristics of the weld (depth, width, cross-sectional
area etc) are controlled by the following parameters:
•
Laser average power.
•
Welding speed.
•
Focused spot size.
Increased power (with other parameters constant) increases weld width, depth and cross-
sectional area.
Increased welding speed decreases depth and cross-sectional area.
Increased focus spot size will increase weld width and decrease depth. In this case, weld
cross-sectional area may not change or may reduce depending on the focused spot
diameter.
10.4 Welding in Modulation Mode
High Peak Power improves processing of reflective and high heat conductivity materials.
When welding aluminium alloys this capability is crucial to developing a stable Melt Puddle
at the focus point, especially when lap welding. The energy is quickly drawn away from the
Melt by the alloy. The variation in surface reflectivity can be quite large due to surface
oxidisation in aluminium alloys. High peak power overcomes these effects thus ensuring a
good process.
Petitioners Canadian Solar Inc. and Canadian Solar (USA) Inc.
Ex. 1025, p. 161
