Laser (Light Amplification by Stimulated Emission of Radiation) cutting is a process in which the light spot is intensely focused onto an object because of the spatial coherence of laser light. This causes an extreme elevation in the temperature of illuminated areas, causing the object to melt rapidly or be vaporized. And thus, a cut or fissure forms in the object.
Years ago, laser cutting was not so prevalent. Other cutting techniques were preferred, including manual cutting. And this is because people were not aware of it. Today, different reports estimate that the market for laser cutting will reach an expected level by 2024. One major reason for the growth of the market size of laser cutting is its processing on a wide variety of materials, such as a medium range of carbon steels, wood, plastic, and ceramics.
The increasing need for laser cutting has introduced various technologies in the industry. So, engineers today have a wide choice of laser, machining principles, and computerized control. This helps them to precisely cut material with high-level accuracy, which wasn’t possible a few years ago.
What are the laser cutting processes and types?
The laser cutting processes are:
Fusion cutting– It uses reaction inhibiting nitrogen or argon as the cutting gas. The advantage of fusion cutting is that it produces a virtually oxide-free cutting edge.
Oxidative cutting– It uses oxygen as an assist gas, increasing heat and reaction rate at the cutting interface. This enables the cutting of thicker material at faster rates but with a less quality surface finish.
Laser scribing– It is primarily used in the electronics industries to process thin films of material.
In these three laser cutting processes, different types of lasers are used such as fiber or solid-state lasers and gas lasers, mainly a CO2 emission gas laser.
Two different types of lasers
CO2 gas emission laser– As one of the highest power continuous wave lasers available for cutting today, CO2 gas emission has been in service for the longest time. Also, it’s a mature technology.
For the functioning of CO2 laser parts, mirrors are needed that reflect the light into a monochromatic stream of light photons of high intensity that exit the laser at the wavelength. Here, water is used to cool the gas tube during stimulated emission and various gasses.
The benefits of CO2 laser cutting are that it cuts thicker materials at equal wattage to fiber and gives superior finishing.
Fiber lasers
In fiber lasers, a type of solid-state laser, the monochromatic and pumped, intensified light is directed and wave-guided down an optical fiber towards the cutting surface. The light is not passed through any gas for stimulated emission.
The basic configuration of the optical circuit of a high-power fiber laser consists of three major sections: Pump section, Oscillator section, and Beam delivery section.
In the pump section, the laser light from pumping laser diodes passes through optical fibers into a high-power pump combiner. The combiner couples the pump light from the laser diodes into a single-mode optical fiber.
In the Oscillator section, the pump light from the high-power pump combiner propagates through a double-clad fiber. Regarding the beam delivery section, it is composed of an optical fiber, passing the laser light from the Oscillator section to a beam coupler.
Choose the right laser cutting process and type for the expected result.