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Introduction
Chapter
1: Introduction to Machining with Lasers
Chapter
2: Time Scales
Chapter
3: Machining with Long Pulses
Chapter
4: Nanosecond Machined Samples
Chapter
5: Machining with Ultrafast Laser Pulses
Chapter
6: Femtosecond Machined Samples
Chapter
7: Contamination, Debris, Etc.
Chapter
8: Heat Affected Zone (HAZ)
Chapter
9: Machining Accuracy
Chapter
10: Sub-micron Features
Chapter
11: Machining Inside Bulk Materials
Chapter
12: Introduction to Waveguides
Chapter
13: Active Waveguides
Chapter
14: Shortcomings of Femtosecond Lasers
Chapter
15: Materials We've Machined
Chapter
16: Conclusion
Appendices:
References
and Glossary |
Long
Pulse Machining Samples
Figure 4.1: A channel made in 1mm thick INVAR (nickel/iron
alloy) with long (nanosecond) pulses.
INVAR,
an alloy formed of Nickel and Iron, has an extremely small
coefficient of thermal expansion at room temperature. INVAR
is often called for in the design of machinery that must be
extremely stable. This sample was machined using a “long”
pulse laser. The laser pulse parameters are: pulse duration
8 ns, energy 0.5 mJ. The machining was not assisted by an
air jet.
It is
quite obvious that the machining process under these conditions
is not very clean. A recast layer can be clearly seen near
the edges of the channel. Large debris are also seen in the
vicinity of the cut. Note that one could have used some type
of an air jet to assist in the machining process. The air
jet function would be to physically project the melt phase
away from the work zone. This would have resulted in a cleaner-looking
cut, but also would have contaminated the sample down-stream.
Source:
Clark-MXR, Inc.
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