Q: Is it becoming more difficult in the automotive sector to achieve sustainability targets? If so, how can additive manufacturing contribute?

Sergio Raso (SR):Sustainability is the overriding aim for the automotive industry. Various core technologies for the future of automotive production have so far been looked at. For example, there is a lightweight hybrid design to achieve weight reduction and fuel efficiency, use of additive methods for a bionically optimised design, and employing tubing and profiles to ensure that the vehicle frame can be manufactured in a highly flexible way.

Dr –Ing Martin Hillebrecht (MH):Toolless additive manufacturing and the profiling method with minimal use of tools may make it possible in future to design all bodywork versions to suit the level of loading and manufacture them “on demand”.

New bodywork structures should weigh less, have high stiffness to ensure performance and satisfy demanding load scenarios in the event of a crash. Whatever happens, there is definitely potential here.

Q: Conservation of resources is a key aspect. How does the automotive manufacturer view this?

MH:With smart lightweight design, particularly with composite construction, vehicles should be roughly 100 kg lighter than their predecessors, depending on the segment of the market. Further weight savings of 10 to 20 percent can be achieved in the bodywork and add-on parts. Many manufacturers have already succeeded in reversing the spiralling trend for increased weight.

But there are still ambitious targets to meet for weight reduction, comfort, functionality, sales criteria and new safety requirements from international legislators. These do not favour lightweight construction. It is a balancing act that we are trying to achieve.

Q: What are some of the advantages and disadvantages of conventional body designs?

MH:In a typical car body with a monocoque construction, panels, reinforcements, mounting plates and profiles are connected together using joining technology. All components act as shells. The required rigidity is produced by cross-sections of metal sheets.

The advantage of this design is the low manufacturing costs associated with industrial mass production, which is the same worldwide. As well as inexpensive semi-finished products made from sheet metal, tried-and-tested and robust technologies such as forming and spot welding are used.

The disadvantage here is that tooling and plant investments only make economic sense if there are large quantities and make it difficult to produce a wide variety of different versions. In addition, tool-specific parts are associated with tooling costs and periods of preparation for the tooling technology are required. Ultimately, the tools have to be available across the full life cycle of the product.

Q: The NextGen spaceframe was produced recently in a project by EDAG, BLM, Laser Zentrum Nord, and Concept Laser, and is part of the EDAG “Light Cocoon” concept car. What features and new processes does this spaceframe have?

Prof Dr-Ing Claus Emmelmann (CE):The jointly-devised spaceframe concept combines the advantages of 3D printing, such as flexibility and the potential for lightweight construction, with the efficiency of a proven conventional profile design. “Selective laser melting” plays the key role in both technologies.

The process yields bionically optimised nodes enable the maximum lightweight construction and a high degree of functional integration. Both the nodes and the profiles can be adapted to new geometries and load requirements without any additional outlay.

This means that they offer the possibility of designing every single part to cater for the level of loading, and not dimensioning the components to reflect the greatest motorisation, as was previously the case. The basic idea then is to have a frame design which can be optimally customised to reflect what the particular model requires.

Frank Herzog (FH):Hybrid construction is also already being used in other sectors. Relatively simple or excessively long geometries are produced by traditional machining, and more complex geometries are then manufactured additively.

This phenomenon reflects the economics. Composite construction is of interest in many sectors where there is a need to bridge a gap between function and economic efficiency.

Q: What new manufacturing strategies and potential for automation will emerge from this in the future? What potential do you see in construction and manufacturing?

The bodywork produced by hybrid additive manufacturing can be
implemented to produce bodyworks that are designed to be
suitable for different load stages.

CE:The potential for construction resides in flexible design that caters for specific load situations. There is also the opportunity to use the bionic structures that have been highlighted to engage in the maximum possible level of lightweight design on a scale that was not previously possible.

At Laser Zentrum Nord we develop design guidelines to be able to successfully transform bionic prototypes such as a bamboo structure or bird-bone structure into sophisticated technical lightweight components with weight savings of generally from 30 to 50 percent.

MH: In addition, being able to respond to fluctuations in sales volumes and “updateable” components during the life cycle of a vehicle should be emphasised. These are completely new ideas for the industry, and are some of the considerations going in to the adaptive “Industry 4.0”. We are excited to see how customers react to this.

FH:The core aspects of “Industry 4.0” such as automation, digitisation and interlinking play a fundamental role in our recently presented “AM Factory of Tomorrow”. The objective is to automate and thus minimise manual processes in order to prevent any downtime in the production of components. Any desired number of machines which were previously designed to be standalone solutions will increasingly be linked together to embrace the notion of a smart factory.

There will also be automation and interlinking of additive and conventional technologies, in particular in the reworking of the components that are produced. Traditional manufacturing methods will then operate alongside additive methods.

This is aligned with the requirements of the basic idea behind Industry 4.0. In the future, this will also make our process economically attractive for the mass production of metallic components, and also apply to the automotive industry, where it is primarily all about large volumes and quantities.

Q: What significance does the powder-based laser melting of metals have today and what significance will it have in the future in the automotive industry?

The bionically optimised and lightweight vehicle structure is
produced by hybrid additive manufacturing, highlighting a new way
in which anadaptable and extremely flexible production concept
can be implemented.

SR:Additive manufacturing techniques are today employed primarily in the automotive industry to manufacture small numbers of functional parts. However, as the aerospace industry has already demonstrated, we can see that the move over to additive manufacturing strategies significantly enhances product and process performance.

The introduction of the “Manufacturing for Functionality” paradigm, along with “just-in-time manufacturing” and precision concepts instead of the rather restrictive “Design for Manufacturing” as well as have already begun to establish a foothold in the automotive industry. We are seeing the foundations of something completely new here.

MH:Presently, additive processes provide great potential in prototyping and tooling, as well as the production of spare parts. These processes have so far not caught on in automobile production yet, likely due to the high prices of materials and machine technologies.

We await the future with keen interest, and would be delighted if the sector were to embrace our ideas of tool-free manufacturing in combination with traditional manufacturing methods. There are definitely lots of opportunities here.

Q: Spare parts for cars are regarded as a logistical and costly challenge. Global availability, warehousing, life cycles and the pressure of time are all challenges for the spare parts experts. Not least, spare parts are currently a blessing for automotive suppliers that operate as OEMs or retrofitters or even duplicators. How can additive manufacturing change this situation?

The X line 2000R from Concept Laser
(build envelope: 800 x 400 x 500 mm3),
equipped with two lasers producing 1kW.

MH:Additive manufacturing makes it possible above all to fabricate components spread out and at different locations. This means that local advantages can be exploited, and different versions can be produced later and close to production. There are thus no transports and logistics costs, different versions of components no longer need to be kept in stock, and production close to the market and customers shortens the delivery time.

CE:Additive manufacturing makes it possible to simply send CAD data records instead of physical components around the world, and if necessary, print out spare parts at a local level. One option is to have decentralised manufacturing, the effects of which we can only imagine. This approach will radically alter the supply of spare parts – delivery times could be reduced significantly and warehousing costs will be completely removed.

This scenario is currently being actively implemented with the aviation industry. The foundation is thus being laid for this approach to be transferred to the automotive industry too.

SR:Car frames based on 3D-bent and cut profiles and nodes produced from additive manufacturing will also enable new paradigms for the management of spare parts and their logistics. Fully automatic production of profiles and nodes based on “just-in-time” approaches would enable a drastic reduction in costs, also assuming that new guidelines for the repair of vehicles will be adopted.

Q: Let’s look at the issue of quality of 3D components. How do you assess the standard of traditional manufacturing methods compared to additive methods?

The NextGen spaceframe nodes can be configured to be
highly functionally integrated thanks to
additive manufacturing.

MH:Standards and quality requirements are being drawn up by industry experts and will undoubtedly also be based on the standards used for traditional manufacturing methods.

FH:It has to be said though: We have a more or less “blank canvas” as far as the additive manufacturing solutions of the future are concerned. But the NextGen spaceframe sends a sufficiently bold signal to the automotive industry to look at the issue more closely in terms of design.

Q: Let’s look ahead to the future. Which additive parts will be conceivable in the automotive sector in the next decade?

MH:Besides the traditional production of prototype parts, like cast parts, additive manufacturing will make it possible to create very complex, functionally integrated and highly efficient structures that cannot be produced using other methods.

So it is worth exploring niche areas and, apart from motor racing and ultra-lightweight construction, looking for future solutions in the context of specific requirements, such as electric mobility. They can then be fleshed out with us as the independent development company for the automotive industry.

SR:All I want to say is that in the future, we will have to accept solutions which cannot be transmitted today. The fact is that 3D printing on space stations is already being explored by NASA. And whatever happens, from a cosmic perspective there is a great deal of future ahead of us.

APMEN Feature, Oct 2016