With exceptionally accurate and consistent output characteristics, Coherent ARM fiber lasers increase production efficiency in the automotive industry and reduce costs.
We constantly hear complaints from automakers and other high-volume OEMs about line-to-line inconsistencies in their laser welding systems that drive them crazy. The bottom line is simple: manufacturers are seeking uniform global manufacturing processes to minimize their costs and, more importantly, the risks associated with safety and product recalls. In their visions, they would have a new assembly line, integrate a laser into it and always achieve the same results. This means that every part, vehicle or weld they produce - regardless of where or when it is made - looks and functions identically.
Unless different welding lasers work exactly the same using identical setups, manufacturers must spend time and money "fine-tuning" the production line and manufacturing process to achieve consistent results from line to line. In addition, manufacturers would like to easily and quickly disseminate process improvements they have developed on one line to all of their facilities around the world without having to spend time on lengthy "fine-tuning" of each line.
The exceptional consistency of Coherent ARM's laser output greatly simplifies implementation
Coherent ARM fiber lasers provide consistency and repeatability
Why do manufacturers turn to Coherent for this problem? Because the unique, patent-protected design of the Coherent ARM fiber laser provides the consistency needed. With the ARM fiber laser, there is no fine-tuning or process compensation required between lasers or branches. All Coherent ARM fiber lasers deliver the same power and other beam characteristics.
How does Coherent do what other fiber laser manufacturers can't? Coherent ARM fiber lasers are designed from the start to provide the operational precision and consistency necessary to achieve low unit costs and high production yields without extraordinary effort. They ensure that once a process flow is developed, the laser will faithfully reproduce it in real-world operation. Each individual unit will deliver consistent output in the same way - every day and on every production line.
How good a laser are we talking about? The chart shows actual data from output power tests of 90 different Coherent ARM fiber lasers. Each was set to output 2.575 kW. The standard deviation of the measured power, as measured by an external power meter, was 5.4 W - just 0.2%. This means that all these lasers would give virtually the same results for a given welding task. This again ensures that the process prescription will be faithfully reproduced over time and on multiple lasers.
Test results of 90 individual Coherent FL-ARM lasers show an extraordinary level of consistency in output power between units.
To achieve this high level of consistency, Coherent has implemented a number of features into the ARM architecture. One key feature is patent-protected independent power control of the ring and center beam - supported by highly sophisticated, separate closed-loop power control for each. The laser uses numerous sensors to measure and control the actual output power for each waveguide and continuously adjust it, maintaining extremely consistent welding performance.
Power control for high-speed applications requires robust and fast control systems. For example, when welding copper to maintain a maximum deviation of 2% penetration depth consistency - even for very thin sheet metal - standard microprocessor control is no longer fast enough. One way to increase the responsiveness of ARM laser control electronics is to incorporate high-speed FPGA (Field Programmable Gate Array) processing technology, which is used in 5G mobile telecommunications. This facilitates accurate monitoring at not just one, but all wavelengths of light generated by the lasers and encountered in the process.
With such high power, speed and control, we must also use some of the most sophisticated laser protection systems on the market. Passive back-reflection protection is largely considered "old news" in fiber lasers today. But the traditional approach used by the rest of the laser industry - namely, simply reducing the laser output power while detecting backscatter - is inadequate for applications that require high precision, yield and repeatability. This is especially true when welding copper and other high reflectivity materials.
Instead, ARM laser resonators use our proprietary device protection technology with an integrated five-stage protection scheme. This approach delivers better stability and less operational sensitivity than the MOPA designs relied upon by less expensive systems. In the case of Coherent ARM lasers, this level of stability and protection truly enables optimal production performance for our customers under all operating conditions.
The unparalleled output consistency and reflection resistance of Coherent ARM fiber lasers enables automotive manufacturers and other high-volume OEMs to meet the most demanding welding challenges head-on.
Learn more about Coherent ARM fiber lasers.
