FEATURE
Issue: 

Master of metal

With Lasys fast approaching, Jessica Rowbury looks at industrial laser processing and finds that solid-state lasers are catching up with CO2 when it comes to cutting thick metals

At a press conference that took place in April in preparation for the laser material processing trade fair, Lasys, the German Engineering Association (VDMA) presented its figures for the business year 2013, showing that the worldwide production volume of laser systems used for material processing achieved by the member companies of VDMA and including such value added contributed by internationally operating companies amounted to €913 million – the highest value since the pre-economic crisis in 2007. This has been attributed to the rise in solid-state systems being used for additional manufacturing processes.

According to Gerhard Hein from the VDMA, these figures not only indicate that there will be a prosperous environment at Lasys when it takes place from 24 to 26 June in Stuttgart, Germany, but that 2014 will also be a successful business period for the laser materials processing market.

However, according to Peter Leibinger, vice chairman of the Trumpf Group and president of its laser technology and electronics division, who will be speaking at the show on how the laser has become a commodity and the subsequent changes in the marketplace, it is questionable whether only companies that are vertically integrated and that are producing high-powered lasers in high volumes will be competitive as the industry witnesses a technological shift.

In the last 10 years, the entry of low-cost laser diodes into the market has been a driver in the rise of solid-state industrial systems, according to Leibinger. ‘There is a rapid shift to novel laser technologies through the introduction of low-cost reliable laser diodes that were not available before,’ he explained. ‘That led to the introduction of fibre and disk lasers, and the replacement of CO2 lasers for cutting − which is the major application − and a rapid price reduction of these types of lasers.’

Until recently, CO2 lasers were the lasers of choice for cutting thicker metals. ‘The cut quality of the 1µm lasers [solid-state] was not satisfactory in thick metals above 5mm – the quality of the cut was inferior to most CO2 laser-based machines,’ said Leibinger. However, the solid-state systems available on the market today are now able to cut thicker metals at a comparable quality to the CO2 systems, along with offering additional improvements. ‘Fibre delivered systems, either fibre- or disk-based, have the advantage of getting the beam to the material in a simple way, and therefore the integration of the laser is a lot simpler than that of a CO2 laser,’ said Leibinger. ‘This, in combination with the fact that a diode-pumped 1µm laser has a much better wall-plug efficiency than a CO2 laser, leads to the quick adaption of that tool in the field.’

And, as solid-state systems are being developed with higher powers, they are fast approaching the cutting quality of a CO2 laser with thicker and thicker materials, according to Klaus Kleine, product line manager for fibre lasers at Coherent: ‘There is some discussion about the surface finish when cutting with CO2 or fibre lasers. In the past, you would see a crossover at around 4 or 6mm, but now you see people getting really good cutting quality at 12 to 20mm with fibre lasers − but if you cut that thick, you are talking about a laser in the 4kW range,’ Kleine explained.

It is because of this capability to cut thicker materials in conjunction with better efficiency and easier integration that approximately 50 per cent of new industrial machines being installed for laser cutting are now solid-state, compared to only 20 to 30 per cent a few years ago. ‘I think today we are at a level of about 50 per cent of new machines being equipped are solid-state lasers,’ stated Leibinger. ‘And I think that will continue − which will drive the high-power laser industry for the coming years.’

However, Leibinger pointed out the challenge that companies face in order to keep up with the change in the marketplace, which he plans to speak about at the Stuttgart Laser Technology Forum (SLT) at Lasys: ‘It is a fast technological shift that is taking place, and the players in the field have to be able to realise this new technology − they have to have a certain depth and breadth in their technological ability in order to develop and produce products based on this new technology,’ he noted. ‘This is especially challenging for some cutting machine manufacturers that make their own CO2 lasers.’

Another way companies will need to ensure their success is with cost structure: ‘I think that you have to be vertically integrated to play a part in this field, and if you don’t have your own diode capability, you are probably not going to be cost competitive,’ Leibinger added.

In order to develop new products and adapt to the changing market, investing in research and development is essential, added VDMA’s Hein: ‘Continuously high capital spending for R&D purposes in the laser section is extremely important. We are now entering fields of application where R&D is crucial, but also very expensive,’ Hein continued. ‘The companies that are intensively active in the area of laser processing are investing heavily, because they have to stand increased competition and are challenging each other in the market.’

But it is not just the technological challenges. A further challenge faced by laser system manufacturers is the shift of demand to Asia, according to Hein. In the figures presented at the Lasys press conference at the end of April, the VDMA reported that for 2013 there was an increase in exports to Asian destinations such as Taiwan, Malaysia, and Korea from a 15 to a 17 per cent market share, which was driven by the electronics industry in the Pacific Rim. ‘We now have a lot of new competition in China and other Asian countries, which have the advantage that they are located in the centre of enormous growth,’ stated Hein. ‘We already see, and will see further, tremendous potential in China, Korea and Japan. We have to cope with this by strengthening our R&D efforts to stay one step ahead. We have to recruit new staff who have the language know-how, the technical abilities, and who are inclined to spend longer in these far markets and to raise the flag for German and European technology.’

CO2 still strong

Although metal cutting accounts for approximately three quarters of uses for laser systems, application areas for CO2 systems still represent a signification proportion of the materials processing market. ‘The CO2 laser still has a huge application field. For the wavelength in the range of a CCO2, some of these lasers in the 10µm range can be used for cutting glass. A 1µm CW fibre laser wouldn’t be able to cut glass that easily,’ said Kleine. ‘A CO2 laser can cut paper and leather and so on, something a fibre laser could never do, because the wavelength does not enable that. I don’t think that the fibre laser is going to cannibalise other product areas – it is an addition to our product portfolio.’

However, fibre lasers are being developed further to be used in a wider variety of applications. ‘There is some work being done with different wavelengths with fibre lasers,’ Kleine said. ‘For example, a 2µm fibre laser could have advantages for processing polymers. A 1µm laser is not that effective at cutting or welding plastic − but a 2µm laser could do plastic welding and cutting.’ The VDMA’s Hein added that there are more applications being taken on by the newer laser technologies: ‘The diode lasers are improving in some special fields such as manufacturing of plastic materials, welding aluminium, and so on.’

It is not just with the solid-state systems where the laser processing industry is witnessing major developments, but also with short and ultrashort pulse lasers, which could lead to more precise manufacturing in the micro-sector, such as in the processing of circuit boards. ‘Short pulsed and ultra short pulsed lasers are opening up an entirely new field of applications in the micro-sector − that is a real asset,’ Hein noted.

‘When I said one of the drivers of the laser sector is the fibre laser, the same is true for this field of application in the micro-sector,’ Hein said, adding that these micro-applications further concrete the need for companies to invest heavily in R&D. I also see a lot of potential for laser sintering and laser melting processes under the headline of laser additive manufacturing.’

Trumpf’s Leibinger also anticipates that ultrashort pulse lasers are showing a high potential for the future: ‘Short pulse lasers will become easier to use, less expensive, and will have higher power − which will lead to more applications,’ he noted. ‘Based on this, the short pulse laser could become a mainstream tool in the coming years.’

One trend that is not expected to continue is the considerable drop in the cost of pump diode lasers that has been apparent over the last few years. ‘I think the massive price reductions that we have seen over the last five years will not continue at that speed, because they were driven by cost reductions of laser diodes themselves,’ explained Leibinger. Currently, from many of the large companies in the market today, diode lasers can be purchased for as little as $3 per Watt of pump power, which has decreased from around $20 per Watt six years ago. Further decreases in cost of the diode would not significantly affect the cost of the complete system, Leibinger added: ‘Today, the cost of the system infrastructure is much higher than the cost of the pump diodes. Therefore, if we further reduce the cost for pump diodes, it is not going to have a major impact on the system price.’

However, Leibinger does not feel as though this will impact the continued trend the industry is seeing in the adoption of solid-state systems: ‘We will see a continuation of the implementation of solid-state lasers for cutting applications,’ he said.

The Lasys trade show in Stuttgart will cover all sectors of material processing, and Hein believes that unlike other international laser shows that feature this field as an addition, the concentration solely on laser processing gives companies a good interactive environment: ‘Lasys is the first show that is focusing uniquely on manufacturing technologies with the use of high power lasers, and I think this makes the difference’ he said.

‘Of course, we have bigger shows for optoelectronics, such as Laser World of Photonics in Munich, but all these shows are focusing on laser manufacturing as an addition compared to the degree of the other products displayed. 

‘Also, Lasys is comprising very focused events with scientific support by high-class research institutes like the Stuttgart Laser Technology Forum and the Lasers in Action Forum,’ Hein continued.

‘Another additional asset is the fact that there are about five automotive-oriented shows taking place in parallel to Lasys, which offer a lot of synergy by attracting potential customers for laser processing technology,’ Hein concluded.

About the author

Jessica Rowbury is a technical writer for Electro Optics, Imaging & Machine Vision Europe and Laser Systems Europe.

You can contact her on jess.rowbury@europascience.com or on +44 (0) 1223 275 476.

Find us on Twitter at @ElectroOptics, @IMVEurope, @LaserSystemsMag and @JessRowbury.