To ensure high-quality laser processing, it is important to pay special attention to the six hidden dangers that exist in laser systems. Measuring the performance of the laser is one of the best ways to avoid these hazards.
Nowadays, the reliability and repeatability of laser processing have enabled manufacturers to produce higher quality parts with greater efficiency.
From sintering in additive manufacturing to component machining in electric cars, the industry is developing new applications for laser technology every day. And as laser technology advances, laser processing becomes more stable, reliable, and commonplace.
However, there are still many hidden dangers in the deployment, operation, or maintenance of industrial laser equipment.
To maintain consistency in laser processing, laser operators may develop a false sense of security and bad habits.
These hazards can be attributed to several different issues, including understanding how lasers behave in material processing applications, understanding the differences between current laser products and traditional laser products, and knowing when and where to measure laser performance. Distinguishing fact from fiction is key to ensuring high-quality laser processing.
Hidden Danger 1
Don’t assume that laser processing today is so stable that it doesn’t require much monitoring (see Figure 1). Material processing applications began to develop soon after the advent of lasers in the 1950s.
Carbon dioxide (CO2) lasers can produce a laser with a wavelength of 10.6μm. With its powerful power, relatively low operating costs and ease of maintenance, CO2 lasers have always been the backbone of laser manufacturing.
Thanks to the extensive operational and safety standards developed by many laser operators that are still in use today, there are still hundreds of thousands of CO2 lasers in use.
In the 1980s, 1μm lasers (fiber lasers, direct semiconductor lasers, and disk lasers) emerged as industrial processing tools. Since then, 1μm lasers have continued to change the development prospects of the industrial laser manufacturing industry. The 1μm fiber laser has high electrical-to-optical conversion efficiency (WPE), high beam quality, and low maintenance requirements.
However, initially it was expensive and could not provide enough output power for industrial laser applications, and it was difficult to maintain. Today, 1μm fiber laser manufacturers have overcome most of these barriers and are providing more practical light sources and systems.
But there is still one issue: as 1μm fiber lasers replace 10μm CO2 lasers in industrial environments, operational and safety standards have not changed accordingly. 1μm lasers cannot be operated and maintained like 10μm lasers.
Today’s laser systems have become more high-quality and reliable, leading users to often overlook the fact that laser systems are still made up of physical parts with physical properties.
The mechanical and electrical components in laser systems gradually degrade or fail after a period of use. The harsh industrial environment is filled with processing waste, which only increases the likelihood and frequency of these component degradation and failures, resulting in decreased efficiency of the laser system and higher operating costs.
Although laser system designers have innovated in managing processing waste, laser users cannot fully understand how the degradation of these system components will affect laser processing without measuring laser system performance, nor can they fully know how and when to take measures to maximize system efficiency.
Laser systems require significant financial investment to rapidly and effectively produce parts. Regular maintenance of the system is essential, and maximizing return on investment requires minimizing the time required for maintenance.
Hidden Danger 2
Many times, relying solely on others to solve laser problems can be costly. For manufacturers, it is especially important to maintain good relationships with industry experts such as application engineers and system integrators.
These experts continually improve methods and translate processing requirements into tools that help manufacturers produce high-quality parts continuously.
However, laser processing may also encounter problems. When using “invisible” tools that are imperceptible to the naked eye, it is always difficult to determine the source of the problem.
When the laser measurement product is not within the scope of troubleshooting, it takes more time and money to restore the system.
In this case, using laser measurement solutions can quickly recoup the cost. These solutions can not only be used to determine the benchmark performance of the laser in the system but also to find the problem with the laser so that the system can be more effectively restored to its benchmark performance.
Integrated laser measurement products help identify changes in laser state, detect trends in laser performance changes to help operators develop more effective maintenance programs, and help troubleshoot problems when they occur.
Another challenge arises from the difference between CO2 lasers and 1μm fiber lasers. The operating wavelength of CO2 lasers is longer at 10.6μm, and their optical systems are very stable, less susceptible to damage from surrounding processing waste and easier to maintain.
Modern fiber lasers, disk lasers, and semiconductor lasers operate at a wavelength of about 1μm, and their optical components are more susceptible to damage from processing waste generated in harsh industrial environments.
Therefore, extreme caution must be exercised when replacing components. Some laser operators are accustomed to using the traditional approach of replacing optical components in CO2 systems, which can easily damage the processing head of a 1μm laser system if not done carefully.
Hidden danger 3
Simply increasing the power of the laser cannot really solve the problem if the laser is not working as needed. As mentioned earlier, this often occurs in CO2 laser applications.
Laser operators understand that “time is money,” and their job performance is often tied to the number of qualified parts produced. When the laser’s performance is poor, laser operators typically take the fastest action to restore the system to normal.
For example, in laser cutting applications, operators typically increase the laser power to maintain normal part production, but this can lead to the following situation:
Due to the long-term operation of the laser system, the optical components may age, become damaged, or contaminated, which greatly increases the thermal effect of the laser system. The thermal effect causes the focused spot to move up, resulting in a decrease in the power density on the workpiece.
Therefore, in the laser cutting process, increasing power can temporarily solve the problem, but it cannot solve the fundamental problem of power consumption.
Beam analyzers allow users to adjust their laser processes to achieve an accurate and sufficient laser intensity while ensuring that the intensity is not too high and causing overheating of the workpiece, thereby achieving optimal processing results.
Today’s laser measurement solutions can help users better understand laser performance and make system operation and maintenance more efficient than ever before (see Figure 2).
Hidden Danger 4
Do not assume that measuring laser systems is expensive and time-consuming.
Many people believe that the return on investment of laser measurement systems is low. This is mainly due to a misunderstanding in people’s minds: that laser measurement solutions are not only expensive but also difficult to set up and use.
There is also a mentality that, although it is good to have laser measurement equipment, it may not provide useful information for applications.
Indeed, the cost of purchasing laser measurement systems used to be high. But today, with advances in camera technology, optical components, networks, communications, computing power, and software, laser measurement products have become smaller, faster, cheaper, and can provide very useful laser information.
Laser power meters and beam analyzers have evolved into cost-effective maintenance tools that can be directly integrated into laser work units.
For example, when welding transmission parts, battery components, or seat components, the laser must always be welded according to the designed processing flow.
Nowadays, automotive manufacturers are increasingly integrating industrial group table power measurement and beam analysis devices into their work units to monitor laser performance regularly, achieve trend analysis, process tracking, and more intelligent maintenance predictions. Manufacturers using these tools will soon realize a significant return on investment.
In addition to cost optimization, there have been improvements to make these products easier to operate. Laser measurement systems are designed with the needs of system integrators, operators, and maintenance personnel in mind.
For example, they use industrial standard communication protocols and are designed with rugged industrial hardware connections.
They also incorporate safety-enhanced designs to prevent damage from processing waste, overheating, and so on.
Laser power meters and beam analyzers are widely used in scientific and research fields, and they are usually designed for research environments. These products can also be used in industrial fields because they can provide relevant laser performance information. This is why these products are designed to adapt to harsher production environments.
Hidden Danger 5
Without laser measurement systems, it is impossible to manage the laser processing process.
In some cases, the development, deployment, and execution of a laser application will simply assume that the laser’s performance remains consistent until problems occur, and then this assumption will be eliminated.
Many consumer markets are requiring reliable, safe products while lowering production costs.
However, achieving consistent laser processing processes for many laser applications, such as rapid focusing/high laser power welding of high reflectance materials, is not always easy because the parameters are very strict.
To ensure that the laser operates with consistent performance, the critical performance of the laser must be measured and analyzed. And take corresponding measures proactively (see Figure 3).
When these laser parameters are not measured and cannot be known, laser processing may deviate from the standard and ultimately result in scrapped parts. For example, in copper welding applications, if the focus spot deviates from its designed position, the loss of workpiece penetration may occur due to the increase in spot size during the welding process.
If the focus spot displacement of the laser system can be tracked, this deviation can be avoided. Sustainability is a major consideration factor. By using resources more wisely to reduce our impact on the earth and striving for intelligent manufacturing.
Anyone involved in these sustainable plans knows that every improvement in the laser processing field is helpful, measuring and analyzing the performance of the laser, and taking action to maintain consistency will provide great help.
A properly maintained laser system will significantly reduce energy consumption and maximize production yields, which not only reduces operating costs but also helps us protect the earth.
Hidden Danger 6
Not all traditional laser measurement techniques have been time-tested and can provide sufficient information about the laser.
Some laser system maintenance personnel still use very simple tools for maintenance and troubleshooting, such as “Power Pucks” laser radiometers.
Acrylic modules and phosphor-coated fluorescent plates are fast and easy-to-use tools, but these traditional tools cannot fully depict the performance of the laser at any specified time.
Using these methods, the laser is directed into a large thermal device and lasts for several seconds to produce a numerical value corresponding to the output power.
The laser beam is imaged onto an acrylic module or fluorescent plate and subjected to subjective analysis without trend data or industry standards. Current electronic laser measurement products can provide time-based measurements, enabling short-term or long-term trend analysis of laser performance.
They are calibrated according to NIST traceable standards and use beam measurement methods that comply with ISO standards. This makes the analysis of laser characteristics more comprehensive and the measurement accuracy more trustworthy.
With the development of Industry 4.0, feedback information from processing tools is very valuable for improving industrial processing. Laser processing systems are no exception.
Laser measurement products can now provide laser performance characteristic information through several different methods.
Measuring laser parameters during processing can provide real-time feedback on the operation of the laser, but usually only analyzes part of the system, providing limited information.
On the other hand, measuring products during processing can more completely analyze the performance of the laser at the processing point, but these products must be used between part processing, so they are essentially not real-time.
Laser users should be encouraged to continuously improve their processes. Practitioners in the manufacturing field have been seeking ways to improve laser processing, including saving processing time and reducing costs, which will directly affect the company’s profitability.
In addition to the challenges of process improvement, lasers can also be difficult to operate, maintain, and troubleshoot. This is why measuring the performance of lasers through independent or integrated products is the best way to achieve these goals.
It is possible to achieve an output power of up to 1.2 kW with the AX fiber laser without reducing beam quality, stability, or reliability. This technology can be scaled to higher power and can also achieve output of other beam shapes.
Although the results presented in this article were achieved in a single-laser configuration of AFX, its advantages also apply to multi-laser configurations (such as dual-laser, quad-laser, eight-laser, etc.).
Multi-laser configurations can significantly improve the production efficiency of L-PBF. AFX improves the performance of L-PBF and paves the way for LPBF to become the main metal additive manufacturing technology.
In addition, AFX has the unique ability to control local microstructure and material properties, enabling the printing of high-quality parts that cannot be achieved by other methods.