Laser Beam Machining Flashcards
What does LASER stand for?
Light Amplification by Stimulated Emission of Radiation.
What are the primary characteristics of laser beams?
Monochromaticity, spatial and temporal coherence, high power density.
Name two output modes of a laser.
Continuous Wave (CW) and Pulsed.
Which factors determine the effectiveness of laser machining?
Wavelength, power density, material reflectivity, and absorption.
What are common materials used in laser machining?
Metals, plastics, ceramics, and composites.
What are two main mechanisms of material removal in laser machining?
Thermal (melting and vaporization) and chemical (breaking molecular bonds).
Name three types of lasers used in machining.
CO2 laser, Nd:YAG laser, and diode lasers.
What is the role of assist gases in laser cutting?
Improve machining rate, prevent oxidation, and enhance surface finish.
List the common assist gases and their roles.
- Oxygen (O2): Enhances cutting speed through exothermic reactions.
- Nitrogen (N2): Prevents oxidation for cleaner cuts.
- Argon (Ar): Used for non-reactive environments.
- Air: Economical but less precise.
What is the plasma shielding effect in laser machining?
High-density plasma formation reduces laser beam absorption, typically occurring at power densities above 10^6 W/cm^2.
Mention a significant disadvantage of laser cutting.
Formation of heat-affected zones (HAZ) and high initial equipment cost.
How does wavelength affect laser cutting?
Shorter wavelengths allow for finer focus points and better precision.
Name industries where laser technology is widely used.
Automotive, aerospace, electronics, medical, and textiles.
What are the components of a laser cutting machine?
- Power supply
- Lenses
- Water chiller
- Fume extraction system
- Assist gas system
