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Keely Portway discovers how laser systems are used in smart manufacturing

The LS4 integrates two laser sources, a 50W green nanosecond and a dual wavelength (near-infrared and green) 10W femtosecond source. (Image: Lasea)

The Smart Manufacturing Leadership Coalition (SMLC) – a coalition of manufacturers, researchers, academics and government laboratories dedicated to smart manufacturing – defines this manufacturing ethos as ‘the ability to solve existing and future problems via an open infrastructure that allows solutions to be implemented at the speed of business, while creating advantaged value’.

This technique is known for the sharing and analysis of data between systems in factories to refine complicated processes and manage supply chains. This allows companies to shift from reactionary to predictive practises in order to improve efficiency, maintenance, wastage and performance.

The smart factory market is expected to rise at a compound annual growth rate of 9.8 per cent, to $244.82bn by 2024, according to analyst Markets and Markets. Some of the driving markets, said the firm’s report, include automotive, aerospace and defence. The latest survey figures from French firm Capgemini cite some 62 per cent of aerospace and defence companies having a smart manufacturing initiative.

Lasers are ideally placed to help manufacturers make the shift to smart manufacturing/Industry 4.0, thanks to their speed, flexibility, precision and ability to be automated. Andreas Gebhardt, a professor at Aachen University of Applied Sciences and an expert on the topic, once said ‘Digitalisation is crying out for a tool that offers the same fast, flexible, and physically unconstrained benefits that it does. And that’s a pretty good description of a laser!’

Ever-present

The Manufacturing Technology Centre (MTC) in the UK, which aims to inspire British manufacturing, believes that laser processing has an effect on almost all aspects of life ‘from sealing crisp bags to fabricating spaceships’, due to its presence as an integral part of almost every industrial sector. The MTC – which has a number of members from various manufacturing sectors and research partners including the University of Birmingham, the University of Nottingham, Loughborough University and TWI – aims to increase the uptake of lasers in ‘high-value’ manufacturing sectors, and its research encompasses applications including welding, cladding, polishing, cleaning, texturing, hardening, machining and micromachining.

The organisation has worked with a number of businesses to help them become Industry 4.0-ready. For example, it has previously worked with vehicle manufacturer Rolls-Royce in developing a production-ready laser welding process to replace an existing resistance welding method to make titanium fairings. The aim was to develop a process and tooling which would reduce or eliminate the need for post welding, part sizing or forming, to improve product consistency, reduce manual input and decrease cycle time. MTC helped the company to design and manufacture a range of assembly tooling with integral argon shielding, and process trials on full-scale parts to produce engine test parts. Rolls-Royce ultimately benefited from a stable, repeatable process to deliver more consistent products.

Finishing touch

More recently, the MTC has assisted surface finishing specialist Fintek to explore mass surface finishing for additively manufactured parts. Additive manufacturing has become more widespread in the migration to Industry 4.0, as it allows for rapid prototyping and 3D printing to produce parts, using advanced computer-aided design software.

It does, however, have its challenges, which is how the project with Fintek came into being. It was felt that there has been a lack of qualified research about mass surface finishing additively manufactured components, which left manufacturers relying on trial and error to achieve the desired finish of these often complex components, at a commercially viable cost. The project was sponsored by government agency Innovate UK, and carried out under the leadership of commercial firm Croft Additive Manufacturing. As well as Fintek and MTC, Liverpool John Moores University (LJMU) added its expertise to the research.

Currently, the quality of surface finish of additively manufactured components can make them unsuitable for some industrial applications. Post-processing, such as CNC machining or linishing of individual surfaces, can be time-consuming and costly.

Louise Geekie, director at Croft Additive Manufacturing, explained: ‘The design freedom of additive manufacturing, where a component is constructed layer-by-layer, allows for increased geometric complexity in the component and other added values, such as light weighting. However, the layer-by-layer manufacture also delivers challenges in that the as-built part is near net shape, and the surface finish is rougher than that of a subtractive machined part. Together, the increased part complexity and the surface roughness of the part create new challenges for finishing to specific surface roughness. This is partly because the surface finish can be different on different facets on a part. Metal additively manufactured components present particular challenges in surface finishing, due to as-built surface finish and increased part complexity.’

The research had two key aims: to reduce the variability and overall surface roughness of an additively manufactured part by optimising the initial build parameters, and so make mass surface finishing more effective and quicker; and to improve mass surface finishing techniques to suit the increased part complexity.

A 316L stainless steel test bar before and after surface treatment. (Image Fintek)

As part of its input in the project, MTC developed a process optimisation system software tool. Mikdam Jamal, from the centre’s digital engineering group, explained: ‘This is designed to help additive manufacturers predict and set the best build parameters to achieve near net shape, while maintaining tensile strength and also reducing initial surface roughness.’

Croft additively manufactured test bars in stainless steel 316L, having defined a series of different laser parameters and build orientations. Surface roughness measurements for each formed basic data to begin the software development, and the process was repeated to create a database. Test bars were also produced for mechanical testing by a team at LJMU, which further processed to surface-finish them in centrifugal disc and drag finishing machines. A further set was provided to Fintek. They were processed in a centrifugal machine, as well as a high-energy stream finishing system. Measurements of surface roughness before and after processing, tensile strength and mechanical properties were then supplied to MTC to help develop the process optimisation system.

Using the data in this way allowed the team to test the additively manufactured parts, and they found that the surface roughness of the build was within six per cent of the software prediction. So, a more accurate prediction of build parameters could be made to enable the creation of a part nearer the net shape from the first build, reducing trial and error work. The surface finish of the part was also improved in the build, subsequently requiring less post-processing time.

‘With the help of Innovate UK,’ said Geekie, ‘a leap forward has been made in understanding the correlation between additive manufacturing build parameters and mass surface finishing. The benefits are more than cost saving, they also come from opening up the areas of additive manufactured part applications that are beyond current technology.’

Helping others think smart

MTC partner the University of Birmingham has been working on a project of its own to aid the move into smart manufacturing. The Smart Factory Hub (SmartFub) is a three-year programme, funded by the European Structural Investment Funds, to support small and medium enterprises in Greater Birmingham and Solihull. Led by Professor Stefan Dimov, the hub has facilities at the university’s Edgbaston campus.

The hub covers six high-impact interrelated technology areas: additive manufacturing, advanced machining, surface engineering, laser processing, industrial automation and digital manufacturing - which Dimov describes as ‘an overreaching enabler for developing new products and processes’.

Under the SmartFub project, the university’s Advanced Manufacturing Technologies to Create, Activate & Automate (AMTECAA) programme is designed to support companies looking to apply advanced manufacturing technologies. Industries covered include automotive, aerospace, oil and gas, and electronics, as well as certain parts of the healthcare sector. The university has enlisted the help of partner manufacturers, including Lasea, HMK and Mazak, to provide physical equipment demonstrators and workshops to local businesses.

In terms of its work using lasers, AMTECAA offers support for companies looking to use additive manufacturing by providing design optimisation in aluminium, stainless steel and titanium. In addition, manufacturers can find out about topology optimisation for lightweighting, materials selection or alloy development, rapid prototyping and material and surface characterisation of additively manufactured parts.

Partner Mazak supplied the project with its i-400 AM Integrex hybrid machine. This combines both metal additive and subtractive manufacturing technologies for custom applications including tool repair, component remanufacturing, cladding of dissimilar materials and the addition of surface features.

The machine integrates direct energy deposition (DED) additive manufacturing technology into a five-axis multi-tasking machine to offer support to companies looking for hybrid technology and subtractive manufacturing in one platform. It uses a built-in 1kW fibre laser to melt metallic powder, which is applied layer-by-layer via interchangeable cladding heads.

Mazak supplied the AMTECAA programme with its i-400 AM Integrex hybrid machine. (Image: Mazak)

Those companies eligible for assistance under the project can also take advantage of the AMTECAA’s expertise when it comes to ablative laser processing. This can help with a variety of practical smart factory applications, as Dimov said: ‘Our Lasea LS4 system with seven axes – five mechanical and two optical – and a femtosecond laser is capable of processing highly complex parts at fast scan rates. We can support companies with laser applications including micro machining and drilling, surface polishing and surface texturing.’

The LS4 comes to the project through its partnership with femtosecond laser technology firm Lasea. It was delivered to the university in spring and is specifically designed for micro-machining applications in industry. It integrates two laser sources, in particular, a 50W green nanosecond and a dual wavelength (near-infrared and green) 10W femtosecond source, to perform micro structuring, patterning and texturing.

The machine is a multi-axis processing platform that incorporates three linear mechanical axes (X, Y, Z), two rotary axes (B, C) and two beam deflectors/optical axes (GX, GY) for executing complex operations on 3D surfaces. The seven axes can all be controlled simultaneously, for example the two optical axes can be used to move the laser beam at high speed, while the substrates are re-positioned synchronously employing the five mechanical axes. These multi-axis processing capabilities make possible not only micro processing of free form surfaces, but also the high precision processing of surfaces that are bigger than the field of view of the focusing lens.

The machine is also equipped with a module called LS-Precess to provide capabilities for cutting and drilling, while controlling the resulting taper on substrates’ sidewalls.

In particular, this module allows a collimated laser beam to be rotated around its axis at high-speed while using the scan head (the two optical axes) simultaneously to move the beam. In this way, cutting and drilling operations can be performed at high speed, while controlling the beam incident angle and therefore achieve zero or negative tapers on sidewalls.

Spanish board manufacturer invests in Industry 4.0

Kuadrotek, part of the Elektra Group, has invested in its Tarragona facility to bring it in line with Industry 4.0.

The company specialises in the design, development and implementation of electric switchboards and control panels for the automation of a variety of industrial processes. It has chosen to partner with Valencia-based TCI Cutting for the work, and is already benefiting from the installation of the laser cutting specialist’s new multipurpose machine for laser cutting and milling.

The combined solution was derived from TCI’s Dreamline Fiber 3D laser cutting machine, and is designed to provide a complete solution of infinite twist, high-power fibre 3D laser cutting, milling and 3D threading. The machine is being used to good effect by Kuadrotek, which had the machine customised for its specific requirements, which include cutting electrical fibre and steel panels, facilitating cutting on flat sheet metal panels in 2D or 3D via its long, vertical Z-axis.

TCI’s Dreamline Fiber 3D laser cutting machine. (Image: TCI)

In addition, the milling head switches between different tool types automatically, which allows drilling, threading and milling on flat and vertical surfaces. With increasing productivity in mind, the machine has two automated tables which can alternate the loading of materials. With enhanced connectivity – including manufacturers’ equipment – Kuadrotek has found the cutting machine ideal for helping it meet its Industry 4.0 ambitions.

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