Laser materials processing
1 Introduction 2 Laser beam Generation
1 Introduction 2 Laser beam Generation
Kartei Details
| Karten | 9 |
|---|---|
| Sprache | English |
| Kategorie | Technik |
| Stufe | Universität |
| Erstellt / Aktualisiert | 07.01.2015 / 07.01.2015 |
| Lizenzierung | Keine Angabe |
| Weblink |
https://card2brain.ch/box/laser_materials_processing
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| Einbinden |
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How is a laser beam defined?
Name the 3 main characteristics.
1. monochromatic (always a precondition for coherence)
2. coherent
3. almost perfectly parallel
In wich "region" can most of the lasers for materials processing be found? Name 3 of those laseres.
What specific dangour results from this characteristic?
The most common lasers for materials processung can be foun in the infrared region. (CO2 - / YAG- / Diode-lasers)
The dangour of infrared (laser) light is the invisibility.
Examples for Laser Materials Processing:
Where can using a laser beam for materials processing be meaningful?
- welding on heat-sensitive parts
- welding or hard-brazing of welds in the "viewing-range" of a product
- transmission laser welding of plastic parts
- laser cutting (eg. Stants)
- laser drilling (for very small diameters)
- laser hardening
How to achieve light emission with only 1 wavelength (=monochromasie)?
Using only one single kind of atoms or molecules and exiting them in one defined way. Some materials then start to emit light in only one defined wavelength.
Suitable materials for the construction of a Laser are those materials, that – when they are pumped with excitation energy – start to emit energy dominantly in form of light (and only in minor amount as heat). These useful materials to construct a laser are called „Gain Media“ or „Laseractive Media“ or „LAM“.
How to achieve coherence and emission into 1 direction?
Place two mirrors around the LAM. Thus, the part of the light-waves which is at random emitted in the axis-direction between the two mirrors don´t leave the LAM. Instead they run through the LAM several times in the 1 unique direction given by the axis between the mirrors.
stimulated emission "LASER-effect"
Laser Amplification by Stimulated Emission of Radiation
Name the main advantages and disadvantages of CO2-Lasers.
CO2-Lasers:
Main specific advantage of CO2-lasers:
Low investment costs per kw laser-power.
Main specific disadvantage of CO2-lasers:
Beam not transportable via fiber-cable. (wavelength is too long for glass-transmission)
Name the main advantages and disadvantages of YAG-Lasers
YAG-Lasers:
Main specific advantage of YAG-lasers:
Many, such as good absorbtion in metals, fiber-cable ability.
Main specific disadvantage of Diode-lasers:
None.
Name the main advantages and disadvantages of Diode-Lasers.
Diode-Lasers:
Main specific advantage of Diode-lasers:
Very compact, best efficiency.
Main specific disadvantage of Diode-lasers:
Lower focusability (poorer beam quality).
