The LMD process uses a focussed laser beam and metal powders to add weld material and build up parts. Through multiple layering techniques, a coating or 3D geometry can be deposited to replace damaged features or manufacture entirely new geometries. Process advantages include a high-integrity fusion bond between the deposited material and the substrate, and very low heat input from the laser beam into the base material. The latter produces a small heat-affected zone, and accurate and reproducible positioning.
Trumpf customers benefit from a range of lasers and laser systems, process expertise, and services for numerous applications, which means LMD technology can also be combined with laser welding or laser cutting. This is indeed the case with the TruLaser Cell 7040 where, thanks to inherent modularity, users can easily switch between cutting, welding and LMD.
TWI, an independent research and technology organisation, will locate the machine at its Rotherham facility on the Advanced Manufacturing Park, where it will be put to work on the Open Architecture Additive Manufacturing (OAAM) project, for which TWI is the lead partner. The OAAM programme plans to develop directed energy deposition (DED) additive manufacturing technologies that can be scaled up to accept multi-metre component sizes for the benefit of UK aerospace. These new platforms will enable aerospace manufacturers and their supply chains to develop advanced additive manufacturing concepts.
“We’ve been running several LMD systems on both industrial robot manipulators and a Trumpf DMD 505 gantry-type 5-axis cell for the past 15 years,” says Dr Carl Hauser, section manager, laser additive manufacturing at TWI. “Although the Trumpf machine still functions perfectly well, joining the OAAM project allowed us to consider our options and specify a new, high-precision system to meet the growing needs of the aerospace industry and TWI member companies. After an assessment, the decision was made to invest in a new large-scale 5-axis gantry facility for laser additive manufacturing.”
Following a public tender, an order was duly placed for a Trumpf TruLaser Cell 7040 with LMD capability.
The TruLaser Cell 7040 destined for TWI features several important modifications that make it unique in the marketplace. Importantly, Trumpf and TWI are working in close co-operation to deliver a system that will meet specific requirements of the OAAM project. This work has led to the specification of a number of critical adjustments to the standard system. For instance, the 1 m Z-axis capacity will be extended to 1.5 m in order to accommodate large aerospace parts; coupled with 4 by 2 m capacity in the X and Y axes.
In addition to the machine’s 5-axis capability, there will be a fully integrated rotate and tilt table, with 1,500 kg load capacity, controlled using special software routines specified by TWI and being developed by Trumpf. This functionality will be further supported by Autodesk, which is developing common CADCAM control interfacing across the OAAM DED technologies. The modularity of the TruLaser Cell will also enable TWI to integrate additional process steps (such as non-destructive inspection systems) for optimum implementation to aerospace requirements.
“The OAAM project will steer the development of large-scale 3D printed aerospace parts, typically aero body and fuselage components, but also engine casings and landing gear parts, for example,” explains Hauser. “The Trumpf machine will be an integral and critical resource to drive our organisation forward, not just on the OAAM project, but for many years beyond.”
The Trumpf TruLaser Cell 7040 is due to arrive at TWI’s Sheffield facility in the summer of 2019.
OAAM, which is supported by Innovate UK, commenced on 1 January 2018 and is scheduled to run for three years.