As the application field of laser cutting technology continues to expand, the types of materials suitable for fiber laser machines are also gradually increasing. Due to the different physical and chemical properties of different materials, special attention should be paid to the corresponding operating points when performing laser cutting. The following is a brief analysis and precautions for several common laser cutting materials:
Ⅰ.Steel
1.Definition of steel:
Steel is one of the common materials used in laser cutting. When using oxygen as the processing gas for fiber laser machine, better cutting results can be obtained. And the cutting edge will be slightly oxidized.
2.Cutting tips:
For steel plates with a thickness of less than 4mm, nitrogen can be used as the processing gas for high-pressure cutting. At this time, the cutting edge will not be oxidized, thereby obtaining a smoother cutting surface. For steel plates with a thickness of more than 10mm, it is recommended to use special plates. And apply an oil film on the surface of the workpiece during processing to improve the cutting effect and quality.
Ⅱ.Stainless steel
1.Definition of stainless steel:
Laser cutting of stainless steel can use oxygen or nitrogen as the processing gas.
2.Cutting tips:
When cutting with oxygen, the edge will oxidize, but this does not affect the use for some application scenarios. When cutting with nitrogen, a non-oxidized and burr-free cutting edge can be obtained without additional processing. Applying an oil film on the surface of stainless steel sheets can improve the perforation effect without reducing the cutting quality.
Ⅲ.Aluminum
1.Definition of aluminum:
Due to its high reflectivity and thermal conductivity, aluminum is difficult to laser cut. Aluminum with a thickness of less than 6mm can be laser cut. And the specific effect depends on the alloy type and the power of the laser.
2.Cutting tips:
When cutting with oxygen, the cut surface becomes rough and hard; when cutting with nitrogen, the cut surface is smoother. Due to the high purity of pure aluminum, it is difficult to cut. It can only be cut when a “reflection absorption” device is installed on the system, otherwise the reflected light may damage the optical components.
Ⅳ.Titanium
Laser cutting of titanium sheets can use hydrogen or nitrogen as the processing gas. The specific parameters can refer to the cutting standards of nickel-chromium steel. When cutting, it is necessary to pay attention to controlling the gas flow and cutting speed to ensure the quality and neatness of the cutting edge.
Ⅴ.Copper and brass
Both copper and brass have high reflectivity and good thermal conductivity. For brass with a thickness of less than 1mm, nitrogen cutting can be used; for copper with a thickness of less than 2mm, oxygen cutting can be used. When laser cutting copper and brass, the system must be equipped with a “reflection absorption” device, otherwise the reflected light will damage the optical components of the laser.
Ⅵ.Synthetic materials
When cutting synthetic materials, it is necessary to pay attention to the possible dangers and harmful emissions during the cutting process. Synthetic materials that can be processed by laser cutting include thermoplastics, thermosetting materials and elastomers. Good ventilation and fume exhaust must be ensured during the cutting process to avoid the accumulation of harmful gases.
Ⅶ.Organic matter
When laser cutting organic materials (such as wood, leather, cardboard and paper), it is necessary to pay attention to the risk of fire. Using nitrogen or compressed air as the processing gas can reduce the risk of fire, but the cutting edge will still appear charred, which appears as a brown edge. The appropriate gas flow and cutting speed should be maintained during cutting to reduce the degree of charring.
Final Thoughts
When laser cutting different materials, it is necessary to select the appropriate processing gas and process parameters according to the characteristics of the material to ensure cutting quality and operational safety. The reflectivity, thermal conductivity, thickness and other factors of different materials will affect the cutting effect, and the operator should adjust and optimize according to the actual situation. Ensuring good equipment maintenance and correct operating methods can improve the efficiency and cutting quality of laser cutting and meet the processing needs of various materials.