Above: made by traditional manufacturing from welded metal sheets. (2) Middle and right: elements made by additive manufacturing using Selective Laser Melting technology. Source: http://www.arup.com/
Introduction
It may appear like a heavyweight boxing fight, on one side of the ring the well-known and massively extended traditional manufacturing technologies, on the other side the astonishing, highly flexible production, non creative constraints, but still questioned 3D printing. It may seem it is going to be like a train crash. So, who will win the fight?
Before the duel starts, let’s take a minute to explain two concepts: 3D printing and Additive Manufacturing.
3D Printing was defined in our previous post What Is 3D Printing and What Are Its Uses? However, it is also possible to find another concept called Additive Manufacturing (AM). But is 3D printing the same as AM? Let’s take a look at what The American Society for Testing and Materials (ASTM) International says about AM:
“A process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies.”
In common practice, the terms “AM” and “3D printing” are used interchangeably.
Additive Manufacturing versus Traditional Manufacturing
In general terms, traditional manufacturing technologies, as machining and casting, provide the highest parts quality level, according to surface finish and geometrical and dimensional accuracy. Even, the mechanical properties are usually better, due to 3d printed parts may be not completely filled by the material. In addition, the AM technologies have a short range of available materials which are usually proprietary. However, the materials variety is continuously expanding while the prizes are decreasing.
In spite of the mentioned drawbacks, 3d printing is building up into the most reputable cutting-edge technology companies within sectors for example aerospace, automotive and medicine. This is possible due to AM does present tremendous opportunities, derived from its exceptional advantages. Some of them are listed below.
The giant airplanes manufacturer Airbus is really betting on AM, as 3D printing plastic and metal parts will allow manufacturing lighter and cheaper parts. Source: http://videos.airbus.com/video/457131e88eds.html
Additive Manufacturing Advantages
Unlimited designs: AM makes possible the manufacture of any design regardless the design complexity and allowing the production of integrated components. This is extremely important towards a wide open-mind design (revolutionary shapes and lighter parts) without considering manufacturing constraints related to machining, moulding, etc. It is said “complexity is free”, because it has not an impact in the manufacturing cost.
Flexible supply chains: production by AM does not need any special tooling neither casting, so shifting the production to a totally different object is completely easy and immediate. Redesigning stages has no influence in the production costs, consequently, it is the ideal manufacturing technology for both prototyping and low volume batch (as low as one if required). This is truly interesting in areas such as product development and low-to-medium volume production, also being the perfect ally for highly personalized customer market.
Herein an example of how 3d printing may lead to non-constraint designs. In this case, GE Aviation is developing a fuel nozzle for the LEAP engine that is up to 25 percent lighter and more complex than its counterparts and combines into one part what previously had 20 small pieces.
Source: GE Aviation – http://www.geaviation.com/company/additive-manufacturing.html
Product development: due to AM does not need specific tooling neither casting any design may be produced in a short period of time under a cost effective perspective. As a result, AM offers product development teams a rapid iteration between designs, assembly and functional tests, bringing about a remarkable decrease in both time and product development costs.
Ford automotive manufacturer is using 3D printing in product development stages (cylinder heads, intake manifolds, air vents, etc), cutting times and costs. Source:https://media.ford.com/content/fordmedia/fna/us/en/news/2013/12/12/ford_s-3d-printed-auto-parts-save-millions–boost-quality.html
Traditional Manufacturing Advantages
Mass production: in terms of high-volume production moulding manufacturing is the right choice. This is because, in spite of the extremely higher fixed costs (derived from tooling and moulds), the variable ones which comes from the massive production (materials and operational) are tremendously more economical. Therefore, in those cases in which the derived costs from tooling and setup cannot be amortized, AM has to be considered.
Parts manufactured quality: traditional manufacturing are a truly mature technology in comparison to AM, which was born 30 years ago. So far, AM manufacturers are seriously working towards to improve some identified drawbacks, such as the part surface finish and the inaccuracies and lack of reproducibility of the processes.
Wide range of materials: there is an unlimited variety of materials available for traditional manufacturing. Currently, just a narrow range of materials are offered for AM (only a few polymers, metals, ceramics and composites). However, there is a huge interest in new materials research and development, hence, the portfolio is constantly growing while the prices are dropping.
Present and future of Additive Manufacturing
After the first rounds, it is difficult to figure out who will be the winner. Each technology has unique advantages which become each one in the best choice for some specific fields.
However, we may find something really fascinating when we combine both technologies as many poor points of the AM may be mended by means of a post finishing treatment. Geometric and dimensional accuracy and surface finishing can be considerably improved by machining, sanding, polishing, abrasive blasting and coating. Mechanical properties and surface quality can significantly enhanced by resin infiltration or electroplating.
DMG MORI has developed a technology capable to combine laser AM and integrated milling in the same work station. Some blades have been milling improving the part quality and the geometrical and dimensional accuracy.
Source: http://www.dmgmori.com/webspecial/journal_2014_2/en/wp-lasertec-65-3d.htm
3d printed plastic part after an electroplating process. The superior mechanical properties and surface finishing expands the 3d printing plastic parts scopes. Source: https://www.stratasysdirect.com/blog/electroplating-goes-beyond-making-fdm-and-polyjet-parts-shine/
There are 3d printers capable to print with conductive inks which allow embedded electronic parts manufacturing.
Source: http://keck.utep.edu/advanced-additive-manufacturing-applications.html
It is known that within the next 10 years AM technologies are going to change the manufacturing process, in which the future supply chains will experience an evolution towards new non-constraint designs and flexibility. Moreover, will appear a new concept of small scale production where parts will be manufactured on demand, on site and based on a highly personalized customer.
Meanwhile, we have to get the most from them and combine with our venerable traditional manufacturing technologies to enhancing the parts properties. So, the smartest answer of the post’s aforementioned headline is: the union makes the force.