Latest posts by Dr James Goddin (see all)
- Speeding up the discovery of new alloys - 20th January 2017
- Optimizing Information Management for Additive Manufacturing - 11th December 2013
Additive manufacturing, often referred to as ‘3-D printing’, is creating great excitement in advanced manufacturing. Use of the technology means that fully functional objects can be built from plastics and metal, layer-by-layer, in extraordinary detail, without the need for expensive moulding and with minimal post-processing required. Research in this area has attracted funding from governmental agencies seeking to establish a competitive advantage and offset the loss of much traditional heavy manufacturing to lower-wage regions. Such projects target increased automation, greater material and energy efficiencies, and a reduction in waste. To meet these targets, many practical challenges must be overcome—effective use of materials information will be an important success factor.
Crossing frontiers with additive manufacturing
Once a niche application for rapid prototyping, additive manufacturing with polymers has established itself in recent years for advanced manufacturing of complex or expensive components. Industries such as medical devices, automotive, and aerospace are now examining the potential of metal and cermet additive manufacturing. Likely benefits include:
- Lower use of materials:
Components are constructed “additively” (layer-by-layer) rather than wastefully machining away from a larger bulk of material. This immediately reduces what the aerospace industry refers to as the ‘buy-to-fly’ ratio (a way of measuring the costs associated with the bulk materials versus those actually used in the finished product).
- Lower use of energy:
Additive manufacturing uses less energy than traditional production techniques, largely due to the elimination of the energy required for moulds and other tooling, etc
- Highly complex structures:
It is often only by such a direct manufacturing approach that components can be constructed with advanced internal voids, cooling channels, and highly complex internal support structures. For example, in August this year, NASA successfully tested a complex rocket engine component made up of only two discrete parts, compared with the previous 115 parts.
Facing up to the challenges
Additive manufacturing is not yet a mature technology and many challenges remain. In particular the differing material properties, layer to layer (e.g., due to thermal history differences) can lead to internal stresses, warping, and failure. When combined with comparatively low build rates these failures can be problematic and costly. These property differences may be due to the build itself, but can also be inherent to the design of the component. Manufacturing refinement therefore requires complicated iteration between the design, the material production, the deposition parameters, and the materials properties themselves. Other problems include controlling the porosity of the material and, in highly-regulated industries such as medical and aerospace, the need for qualification of new materials.
How can such problems be solved? Improving detailed understanding of the relevant materials structure and processes will help. Two factors that can support this understanding are computer simulation and the availability and effective analysis of increased volumes of high quality experimental data. In both cases, large quantities of complex and rather specialist information must be generated, captured, managed, shared, and used. This isn’t just a matter of capturing property values in a spreadsheet or database—in experimental programs, for example, the full processing history of thousands of samples and parts must be captured, linked to related test results and analyses, and this full body of data must be made searchable and analyzable. This is itself a considerable challenge.
The good news is that the challenge of managing and applying materials information for complex processes is not without precedent. Granta Design, for example, has for many years helped aerospace and defense organizations manage and apply their advanced metals and composites information. And this experience has proved useful when applied to the field of additive manufacturing, where Granta has partnered in four European Framework Seven projects, MANUDIRECT, StepUp, NANOMICRO and AMAZE.
The recently completed NANOMICRO project focused on a layer-wise manufacturing approach using highly focalized powder/heat fluxes (with dimensions in the microns range) for metals and cermets. Granta applied its materials information technology expertise to ‘synthesize’ the properties of virtual materials on a computer. Combined with computational models developed with the University of Cambridge, this enables simulation of the changing thermal history of individual additively manufactured components. Constructing a database of the resulting properties subsequently enabled the correct build parameters to be ascertained, shortening the development time required to obtain the correct production parameters.
Granta are also partners in one of the largest collaborative programmes in the world focused on additive manufacturing—the AMAZE project (Additive Manufacturing Aiming Towards Zero Waste & Efficient Production of High-Tech Metal Products). Led by the European Space Agency, this 30 partner project seeks to develop the best quality, best designed and most resource-efficient metal products ever made and turn additive manufacturing into an automated mainstream process for use in aeronautics, space, nuclear fusion, automotive, and tooling applications. Launched in January 2013, the project seeks to achieve 50% cost reduction for finished parts, and 50% reduction in power, consumables, raw materials and machining, compared to traditional metals processing. Granta Design’s primary role is to manage the materials, processing, and test information for analysis and simulation, tailored uniquely for Additive Manufacturing. The information software platform will establish the first collaborative resource for state-of-the-art research, development and production for the European Additive Manufacturing community.
Printing the future?
According to the 2013 Wohlers Report, the global additive manufacturing market is projected to grow five-fold from $2.2 billion in 2012 to an estimated $10.8 billion in 2021. Some of the growth in this industry will be due to the way that any engineer or researcher, with the right equipment, can construct highly individual and complex one-off products. There are currently lots of fun examples of the potential of these methods, such as the 3D-printed electric guitars, keyboard and drum kit played at the December 2013 Euromold conference, as reported by the Economist. More practically, “in office 3-D printing” is already making a difference in areas such as dentistry. What if today’s research can bring these approaches to bear on the complex components used in the automotive and aerospace industries? Additive manufacturing may even go into space, with proposals to produce products “in situ” in places as extreme as the international space station – next year sees the launch into space of a polymer 3-D printer. The AMAZE project means a space-based metal 3D-printer might one day be a possibility too.
A combination of simulations and careful analysis of hundreds of test results has already led to improvements in product reliability and reduced build times. Materials information and its management will continue to play an important role in enabling the continuation of this work. While there are still considerable challenges to overcome, especially in the field of metallic additive manufacture, applying this expertise should mean the sky is no longer the limit for additive manufacturing.
Read more about Granta for Additive Manufacturing.