Rapid manufacturing - additive manufacturing developments and applications

Rapid technologies, such as additive layer manufacturing for direct part production, continue to grow, as more and more industries begin to appreciate the benefits afforded by these innovative processes, not least the aerospace sector. The ability to produce components in materials such as hot work steels, stainless steel, cobalt chromes, Inconel, titanium and aluminium alloys presents the aerospace industry with immense potential for direct part production using ALM. Realising the opportunity, Birmingham-based Material Solutions operates an ALM applications development centre, with particular focus on the aerospace sector. "ALM in high performance metals is well suited for complex, thin-walled structures in gas turbines," explains Carl Brancher, CEO of Material Solutions. "However, as a new technology, it is not yet well understood or validated by potential users. Materials Solutions is bridging this gap by providing manufactured parts, consulting (principally to the aerospace market), and working with equipment and material vendors to develop the technology for mass production." AEROSPACE PRESSURE With ongoing pressure from aerospace manufacturers to develop the capability to produce large parts, Material Solutions turned to Concept Laser to explore this potential using its M3 linear system, available in the UK from ES Technology (01327 701107). Using the M3 linear, Material Solutions set out to design a test component that would qualify certain build criteria, and which could also be used to educate and inform aerospace engineers of 'additive friendly' design features and techniques. Image: A test component that qualifies criteria and educates engineers The finished component demonstrated the current capabilities of the technology in terms of size (300 mm diameter), accuracy and surface finish. While the part does not yet satisfy the ultimate demands of aerospace manufacturers, it clearly confirms the capabilities of the process. Ultimately, the success of the exercise and the current collaboration between Material Solutions and Concept Laser will be used to define the future strategies and technical milestones that will eventually see parts manufactured by ALM techniques leave the laboratory and take to the air. A sector currently more accepting of additive manufacturing is motorsport, and the benefits available to this industry were ably demonstrated recently by the University of Warwick, which reduced the weight of its race car for the Formula Student challenge (run by the Institution of Mechanical Engineers) by 10%, using laser sintered titanium, Inconel and alumide. Here, laser sintering machine and powder producer EOS (01926 623107), played a major role in helping the university move up the field. Several years ago, an EOSINT P380 was purchased to produce plastic components for the race cars in short timeframes. Then, last year, EOS, in its role as technical partner, contributed further by manufacturing and supplying laser sintered metal components: titanium alloy and carbon fibre replaced hardened steel in the production of the half shafts driving the two front wheels; Inconel was substituted for steel tubing, when producing the exhaust header; and laser sintered alumide was used instead of a casting or fabrication for the induction system. Image: One of the new half shafts 3D PRINTING FOR RACERS Aston Martin Racing has also benefited recently from the adoption of rapid manufacturing techniques, this time in the form of 3D printed components. The use of Stratasys FDM technology from Laser Lines (01295 672500) enabled AMR to develop its LMP1 race car in less than six months. The company's Dimension 3D printer was used to mock up the chassis, driver controls and engine of the race car, which is now being driven by the Aston Martin Racing works team drivers in the 2011 Intercontinental Le Mans Cup (ILMC) – a series of seven races spread across the year. AMR selected the machine for its rapid prototyping capabilities after seeing the speed and quality of the parts produced for the Prodrive-run rally team in a previous project. The team is now also exploring the idea of using the 3D printer to make finished parts for the car. One item being considered is the front wing splitters used for aerodynamic flow. The rapid rise of 3D printing for engineered products is nothing short of remarkable, as proven by the diverse range of niche applications it finds. For instance, an Objet Connex350 system that jets multiple model materials simultaneously has been installed at the Nottingham headquarters of swimwear specialist Speedo. Sold and installed by Objet's UK distributor OPS (01283 585955), the machine has taken up residence within Aqualab, Speedo's R&D facility, where it has reduced prototyping time and costs significantly for swim products, such as goggles. Image: OPS - Reducing development times for Speed "We like the multi-materials capability of the Objet Connex 3D printer, as well as its potential to mix material hardness for the purpose of trials," says Dr Tom Waller, head of Aqualab. The Connex350 offers the ability to print parts and assemblies made of multiple model materials, with different mechanical or physical properties, in a single build. Taking the concept even further, the Connex350 can also fabricate 'Digital Materials' on the fly, enabling users to create composite materials that have preset combinations of mechanical properties. The Connex350 is used nearly every day at Speedo, allowing prototypes to go from CAD model in the morning to 'in the pool' by the afternoon. Build times for a typical set of goggles are around 3-7 hours, depending on size and quantity. The production materials for Speedo goggles are silicones and thermoplastic rubbers, all of which are replicated by Objet materials. Of course, when parts in actual materials are required, then emphasis shifts to rapid manufacturing specialists such as Midas Pattern Company (01234 358394), which offers low cost, high quality tooling systems for producing prototype (FASTrim) and production (MRIM) volumes of polyurethane RIM mouldings. FAST RESPONSE Recently, the company successfully implemented a project to supply sets of covers to Prior Scientific – for a new instrument for nano-particle analysis and characterisation applications. Prior knew that an expert manufacturer would be required to produce the covers. The relatively low volumes could not be cost- effectively manufactured by conventional mould shops, and tight tolerances were required to achieve the interlocking functionality and the removal of the top cover for loading and service of the laser module. Furthermore, a quick response was needed – fortunately, Midas was able to respond to the call and supplied the first batch ready for product launch at a US exhibition. The story is similar at Parrot, which, during the first stages of developing its AR Drone (a Wi-Fi toy flying machine), turned to Protomold, a service by Proto Labs (01952 683031), for fully functioning prototype injection-moulded parts. Image: Fully functioning prototype injection moulded parts were the requirement from Prot Labs Parrot mechanical design engineer Guillaume Savoye says: "We very much appreciated the technical suggestions proposed by the Proto Labs team for improving 'mouldability'. It was particularly important for us to validate the concept with 'right material' parts as soon as possible. These enabled us to check the assembly of the different parts and carry out performance tests prior to production." First published in Machinery, July 2011