Introduction
Laser Beam Machining (LBM) uses high-energy laser beams to process materials. It plays a key role in modern manufacturing. This article explores its principles, advantages, applications, and future trends.
Laser beam: a special beam of light
Laser (Light Amplification by Stimulated Emission of Radiation) means “light amplification by stimulated emission of radiation”. It is a kind of light with high directionality, monochromaticity, coherence and high brightness.
Monochromaticity:Â The laser has a single wavelength, pure color, and concentrated energy.
Coherence:Â The phase of laser light waves is consistent and the interference effect is
High brightness:Â Laser energy is highly concentrated and its brightness can reach a million times that of sunlight.
High directivity:Â The laser beam has a very small divergence angle and propagates almost in parallel, making it easy to focus into a very small spot.
Physical Theory Analysis
Principle of stimulated radiation : atoms or molecules are excited by external energy and jump from low energy level to high energy level.
Spontaneous emission : Particles at high energy levels are unstable and spontaneously emit photons back to lower energy levels.
Conditions for stimulated emission : If the incident photon energy matches the energy level difference, stimulated emission will be induced.
Photon characteristics : The photons generated by stimulated radiation have exactly the same frequency, phase, and polarization state as the incident photons.
Function of the optical resonant cavity : Through feedback amplification of the resonant cavity, laser output is finally formed.
Why choose laser beam for processing?
High precision:Â The laser beam can be focused to a micron-level spot, achieving micron or even nanometer-level processing accuracy.
Non-contact processing: The laser beam focuses to a micron-level spot, enabling micron or nanometer-level precision in processing.
High energy density:Â The laser energy is highly concentrated, which can achieve high-speed processing with high efficiency.
Strong flexibility:Â The laser beam is easy to control, can process complex shapes, and can be easily automated.
Wide range of applications:Â can process a variety of materials such as metals, non-metals, ceramics, composite materials, etc.
Materials and applications of laser beam processing
Metal materials:Steel, aluminum, and titanium alloys are used for cutting, welding, punching, and surface treatments. Applied in automotive, aerospace, and electronics industries.
Non-metallic materials:Â plastic, wood, glass, ceramics, etc., used for cutting, marking, engraving, etc., used in packaging, decoration, handicraft production and other fields.
Composite materials:Â Carbon fiber composite materials, glass fiber composite materials, etc., used for cutting, punching, surface treatment, etc., used in aerospace, automobile manufacturing and other fields.
Advanced Laser Beam Processing Technology
Ultrafast laser processing:Â Processing with ultrashort pulse lasers such as femtosecond lasers and picosecond lasers can achieve more precise and higher-quality processing effects.
Laser additive manufacturing:Â Using a laser beam to melt metal powder or wire layer by layer to directly produce three-dimensional solid parts, also known as 3D printing.
Laser micro-nano processing:Â using laser beams to perform micron or even nanometer scale processing, which is applied in microelectronics, optoelectronics, biomedicine and other fields.
