Faster and More Precise Laser Cutting of CrNi steel
The demands placed on modern manufacturing processes are constantly increasing. Especially in laser cutting of challenging materials such as stainless steel (CrNi steel), companies face a classic trade-off: high cutting speed versus excellent cut quality. This is precisely where an innovative technology is gaining traction—axial dynamic beam shaping (DBS).
Challenges in Conventional Laser Cutting
Traditional laser cutting processes typically rely on a Gaussian beam profile. However, as material thickness increases, several drawbacks become apparent:
- Burr formation, particularly nano-burr at the bottom edge
- Poor cut edge quality
- Limited process speed due to saturation effects
These issues not only increase post-processing effort but also negatively impact downstream processes such as coating or painting.
What Is Axial Dynamic Beam Shaping?
Axial dynamic beam shaping is an advanced beam shaping technique in which the laser beam is dynamically modulated along its propagation axis. Unlike static beam shaping, DBS allows real-time adjustment of the intensity distribution within the material.
The key advantage: instead of a point-like focus, an elongated “line focus” is created. This leads to a more uniform energy distribution along the cutting front.
Technologically, this is achieved using highly dynamic optical systems capable of oscillating the beam at kilohertz frequencies. Control is simplified to just a few parameters:
- Oscillation amplitude
- Frequency
- Offset
This reduced complexity facilitates integration into existing systems.
Significant Quality Improvements in Practice
The impact of axial DBS on cut quality is substantial. Experimental results in cutting 10 mm thick stainless steel show:
- Reduction of nano-burr by a factor of 11
- Surface roughness reduced by more than 50%
- No visible burr adhesion
The drastic reduction of nano-burr is particularly important. This fine burr can impair coating adhesion and reduce long-term corrosion resistance. DBS effectively minimizes this issue.
Beam simulation with a static focus (left) and with axial DBS (right):
Higher Speed with Lower Energy Input
Physical Background: Optimized Energy Distribution
Increased Process Stability
In addition to quality improvements, axial beam shaping significantly enhances productivity:
- Up to 82% higher cutting speed at lower power (8 kW)
- Around 37% higher speed at high power (20 kW)
Another critical benefit is the shift of the saturation effect. In conventional processes, increasing laser power eventually no longer results in higher cutting speeds. DBS enables more efficient energy utilization.
In practical terms:
The same or higher cutting speeds can be achieved with lower laser power.
The core of these improvements lies in the modified intensity distribution of the laser beam. While a static focus concentrates energy in a small area, axial DBS distributes it along the beam axis.
This leads to:
- Extended Rayleigh length → more stable process
- Larger effective focus diameter → improved material interaction
- More uniform energy input → more efficient melt ejection
Together, these effects ensure more consistent melting and removal of material.
An often overlooked advantage of axial DBS is its improved robustness. Variations in:
- Focus position
- Nozzle distance
have significantly less impact on cut quality. This increases process reliability and reduces scrap and downtime.
In industrial series production, this stability translates directly into economic benefits.
Increase in cutting speed (left) and reduction of burr formation (right) as a function of laser power, with and without axial DBS using the Zwobbel® system.
Economic Advantages for Industry
The combination of higher speed, better quality, and improved robustness results in clear economic gains:
- Reduced post-processing effort
- Lower energy consumption
- Higher machine productivity
- Improved component quality
Companies adopting this technology can significantly enhance their competitiveness.
Conclusion: A Technology with Strong Future Potential
Axial dynamic beam shaping represents a major advancement in laser cutting technology. It addresses key limitations of conventional processes while unlocking new optimization potential. Particularly in cutting stainless steel, the benefits are clear: reduced nano-burr, higher cutting speeds, and improved process stability. For companies in sheet metal processing, the path forward is evident: those aiming to maximize both efficiency and quality should actively integrate axial DBS into their production processes. The technology is ready for industrial use—and poised to become a new standard.