What is Laser Welding ?

The term LASER is the acronym of Light Amplification by Stimulated Emission of Radiation.

Laser light features its purity and intensity. As it is controllable, it offers the wide range of applications such as processing, measurement, communication, recording, medical treatment and so on. Utilizing laser is expected to expand more than ever.

Laser Processing
Machining and processing which utilize the laser are removing (such as marking, cutting, drilling, trimming, scribing), joining (welding, brazing and resin-bonding) and surface processing (such as quenching, cladding).

The features of the laser processing and machining are:
1. Ultra-precision machining.
2. Less deformation of workpiece owing to non-contact machining.
3. No need of welding electrode maintenance which is needed for resistance welding.
4. Easy processing of different metals, non-conductive materials.
5. No heat distortion owing to short period of joining time.

Features of YAG Laser
YAG laser is generated when a YAG (yttrium-aluminum-garnet crystal) is excited. A YAG crystal is regarded as one of the most excellent one because it shows various oscillation behavior and also presents excellent characteristics.

• Transmittable through an optical fiber
The YAG laser light is transmitted using optical fibers, resulting in easy remote processing and simplified system.
The laser can be set up easily in factory automated system. A single unit offers simultaneous multipoint welding (power-sharing delivery welding) and time-scheduled welding (time-sharing delivery welding)
At present, no optical fiber can transmit a high-power CO₂ laser light for laser processing.

• Invisible light.
Laser light is an infrared light of 1064 nanometer (1.064 micrometer) wavelength.

• Suitable for micro-processing.
The YAG laser does not diverge but proceeds straight. As the wavelength (1.06μm) is one tenth of CO₂ laser wavelength (10.6μm), the YAG laser can be focused to a fine beam, leading to micro-processing.

Oscillation patterns of YAG laser
• Continuous oscillation : Outputs the laser continuously.
• Pulse oscillation : Pulses the laser. As a high output is obtained, this pulse oscillation is suitable for less-absorbing materials such as aluminum, copper. Also it is a good choice for seam welding and spot welding.
• Q-switched pulse oscillation : Stores energy using Q switch and outputs a high peak energy in a short period of time.