When processing metal sheets with a fiber laser cutter, the first step is often to create a small hole (perforation) before the cutting process can begin. There are two primary methods for perforation: blast perforation and pulse perforation. Each method has its advantages and is suitable for different applications. Below, we will explore these two perforation techniques in detail.
1. Blast Perforation
Blast perforation involves continuous laser irradiation on the material surface, forming a pit in the center. A high-pressure oxygen stream then rapidly removes the molten metal, creating a hole.
Hole Size & Plate Thickness Relationship:
The diameter of a blast perforation is typically about half the thickness of the material. For example, a 10mm thick plate will produce a hole around 5mm in diameter. As a result, thicker materials generate larger holes, making this method less suitable for high-precision applications where small, clean holes are required.
Advantages & Limitations:
- Fast perforation speed – Suitable for industrial applications where speed is prioritized over precision.
- Larger hole size – Not ideal for fine machining or thin materials where precision is critical.
2. Pulse Perforation
Pulse perforation uses a high-peak-power pulsed laser to gradually melt or vaporize the material. Each laser pulse removes a small amount of metal, slowly penetrating the sheet until a hole is formed.
Process Characteristics:
- Smaller, more precise holes – The hole diameter is much smaller compared to blast perforation, making it ideal for high-accuracy cutting.
- Slower perforation speed – Thicker materials may take several seconds to penetrate fully.
- Requires gas control – After perforation, the assist gas must be quickly switched to oxygen for cutting.
Optimizing Pulse Perforation Quality:
To ensure a smooth transition from perforation to cutting, the following parameters can be adjusted:
- Pulse width – Controls the duration of each laser burst.
- Pulse frequency – Adjusts how often the laser pulses are emitted.
- Combined adjustments – Fine-tuning both pulse width and frequency can improve perforation quality.
Choosing the Right Perforation Method
- Blast perforation is best for thicker materials where speed is more important than hole precision.
- Pulse perforation is ideal for high-precision applications, such as thin sheets or intricate designs requiring clean, small holes.
Conclusion
Understanding these two perforation methods helps optimize the laser cutting process for different material types and precision requirements. If you need further guidance on selecting the best perforation technique for your application, feel free to contact us rayther@raytherlasercutter.com for expert advice and advanced laser cutting solutions!
-- Rayther Laser Allen Wang