Laser-Cutting and its Heat Affected Zone
Laser cutting is a precision process that uses high-energy laser beam to cut through materials. It is one of the more accurate cutting processes P, which uses focused and concentrated laser beams to cut materials accurately. This laser cutting technology is highly versatile and is suited to a wide range of applications such as cutting sheet metals, plastics, ceramics, glass and more.
When using laser cutting, heat affected zones (HAZs) are created around the cut line. In general, the HAZ is defined as the area outside the laser cut that may have been affected by the particles associated with the laser beam. It is the area of material that has been softened, melted, or burnt by the heat generated by the laser cutting process.
The size and shape of the HAZ depend on a number of factors, such as the materials used, the laser power and its wavelength, the focus depth and shape, the relative movement of the laser focus and the target materials, and the thermal conductivity of the materials. The HAZ is most significant in materials with low thermal conductivity, such as plastics.
While some materials (such as metals) can significantly reduce the size of their HAZs by using a lower laser power, the HAZ of most materials can be reduced by increasing the cutting speed of the laser. The higher the cutting speed, the lower the temperature, resulting in a smaller HAZ.
The extent and composition of the HAZ is important, as it affects the properties of the cut materials. For instance, if the cutline has a large HAZ, it could cause the materials to warp or crack, which would weaken and reduce the usability of the material. It can also reduce the material’s structural strength, lead to oxidation, or affect the appearance of the cut.
Additionally, it is important to note that laser cutting creates a thin slit or kerf on the cut materials, which can be further widened by a burring effect. Depending on the material and beam wavelength, these burrs may affect the usability of the cut materials. Therefore, special attention to the HAZ, slits and burrs should be made during the laser cutting process.
One common method to reduce heat-affected zones and burrs is to use an assist gas such as nitrogen, oxygen, or argon to help evaporate the beams more quickly and keep the HAZs around the cut line minimized. This gas also helps to keep the materials from sticking to the edges of the cut, which can further reduce burring in the laser cutting process.
Laser cutting is a versatile tool and can be used in a range of operations. The key to achieving the best results with this process is to understand the importance of the heat affected zone, and to make sure the right techniques are used to reduce it. With the right techniques, laser cutting can be used to achieve highly accurate and precision results in a variety of materials.