Additive Technologies

Additive manufacturing technologies: A miracle or a soap bubble of industry 4.0

Additive technologies (AT) – are the most dynamically developing branch of production nowadays. We can see that 3D printers are appearing in offices and households, equipment and material sales are growing exponentially, new technologies are announcing, old exclusives are becoming a public domain; all that factors are opening the floodgates to new manufacturers. In spite of the fact that, new services companies are instantiated and big words about the clue role of AT in the Industry 4.0 sound at the exhibitions and conferences, the real situation is not so bloomy especially in Russian industry.
31 march 2019

Let’s specify several challenges in that segment. The removal of technical restrictions, which are typical for traditional technologies, comes with other restrictions. The cost of part`s producing and its components by using AT usually many times exceeds the cost of traditional alternatives. Herewith the difficulty of technological processes leaves a mark on the quality of producing of parts; that is way the prime cost increases even more. In addition, in the context of sanction restrictions the access to foreign stocks is complicated, resulting in raise difficulties for non-state manufacturing companies on the domestic market of materials. The lack of standards does not allow using technologies in extensive production.

As a result, business owners often choose the traditional methods of manufacturing, which had already been defined in checklists according to standards and design documents, instead of any additive technologies.

Service providers, with equipment stock, are complaining about the lack of orders. Equipment, which was bought on the wave of the public excitement, now is standing idle, printing souvenir goods from time to time. Only a few of companies are able to integrate this technology into their workflow.

The question arises as to whether: are the additive technologies a miracle or just a soap bubble in the Fourth Industrial Revolution?

Answering the previous question, we should get purchase on the reasons which are inhibiting to achieve both technical and economical effects. Let’s have a look on the most popular additive manufacturing technology- Selective laser melting (SLM).

Here are principal barriers on the way to economical and technological effects of the introduction of SLM:

  • Conservative approach to prototyping subject to restriction relating to traditional technologies;
  • Conservative approach to the description of part specification;
  • The complexity of a 3d model preparation to manufacturing process (geometry optimization, projecting across the platform, planning the supporting bodies);
  • The complexity of technical process connecting with huge variety of settings requiring an accurate control (laser power, speed and strategy of scanning, the atmosphere of gases inside a chamber)
  • The necessity for accurate control of the quality of the materials used (sphericity, grain size distribution, additive analyzing).   

From my point of view, conservative approach to prototyping is the main reason for market`s unwillingness to AT technologies implementation. The cost of parts` printing by either subtractive technologies (machine processing) or investment casting in only limited number of cases could be cheaper than traditional methods.

It is possible to reduce the price due to geometry optimization in favor of mass reduction, merging of several assembly components into one part. Thanks to this, the manufacturing process is less labor intensive and it offers a unique functionality, it is possible, for example, through inside core and pipes designing or providing special material structure inside or on the surface of a part.

Usually, working with such cases, we ask our clients to describe their “ideal part” in the context of optimal fulfillment of part`s functions without including any technical restrictions. The problem is that it is often impossible for human`s mind to solve this task. However, we successfully overcome this problem by using methodology of additive planning in conjunction with special software tools. 

This example clearly demonstrates the opportunities of prototyping reformulation by the aid of methodology of additive planning. This is effective due to topological optimization and merging of several assembly components into one part. The printed part combined 4 details and 16 fixing elements thereby the mass was 5 times less.

Generally, the terms “topology optimization” and “bionic design” have been firmly rooted in the constructor`s vocabulary. All software tools that are now available on the market are being actively explored in a business environment. Universities are running experiments in reproducibility of optimization results and  mathematical calculation with current information on stability; new staff training educational programs appear.

Bionic design looks at the solutions nature has found and adapts these biological models, systems and elements to solve engineering problems.

Topology optimization of car`s lever with the use of software development CATORO, as a result the mass was reduced twice, while its strengths practically remain the same.

CAE systems involve different mathematical models (mechanics of deformable solids, fluid mechanics etc.) using which the behavior of real objects could be model with high precision. As a result quantity of real tests have been reduced and replaced by computer modeling.

There are two types of CAE systems: high-powered systems with huge amount of mathematical models and field-specific systems. As a rule, the more mathematical models fixed into a CAE system, the more time is necessary to educate employees and integrate it into an enterprise.

The next thing, that is incompatible with techniques application, is its complexity, from the point of supporting long-term process reliability, and also understanding of its specialties and qualifications.

Some people think, that 3d printer is working like usual printing device, you just have to load a 3d model, press button START and right that time you will get a perfectly made part. In fact the satiation is much more complicated. The result depends on designer and operator`s qualification.

Selective laser melting process is full of pitfalls and connected with the high thermal loads, therefore the most important issue is a voltage sensing, which arises during production. The lack of qualification in this case can lead to deformation of a part. That certainly will raise the cost of production, on the condition that it would be possible to produce the part at the manufacturing tolerance point.

For many years the solution of this problem was reduced to machine operator`s accumulated experience and his understanding of material`s modification of thermo physical features under high thermal loads. Reject rate is very high in case of frequent shifts in product mix that are peculiar to that producing method.

Today special soft ware tools, guaranteeing fast and effective prototyping of 3d model for producing, are the solution of this problem.

Automatic optimization of orientating a part in the build platform, optimization of scaffolds with an option to produce variable density of perforations depending on overheating and warping,  introducing cutouts to the design and modeling of the process in order to estimate part`s warping and shrinkage. These strategies will reduce the overall cost of the part, as less material is used.

Methodology which was described above together with software instruments will bring technological and economical benefits from implementation of additive technologies into existent company infrastructure. However, transition process may take months or years if needed in product certification comprising part produced with AT.

Conservative format of parts` specification description also bring some restrictions during using additive technologies. Today the most part of design documents is worked out in the form of two-dimensional projects in a format of drawings supplemented by 3d models. At the stage of preparation for production, this format claims co-operative work from engineer, technologist and operator, as the machine is not able to read drawings.

In 2015 year company group from this technological segment formed a consortium to produce files` new format 3MF, which will address the issue of descriptive format in the future. A syndicate consists of 3D Systems, Autodesk, Dassault Syst mes, FIT AG, GE Global Research, HP, Materialise, Microsoft Corporation, Shapeways, Siemens PLM Software, SLM Solutions Group AG, Stratasys and Ultimaker.

The purpose of the consortium is to define the format that will allow design applications to send full-fidelity 3D models to a mix of other applications, platforms, services and printers.

That file`s format will contain the following information: 3d model, fundamental properties, digital signing (its certificate and origin), settings of machine, drawing, 3d texture and additional metadata.  

Developing of this file format will be the driving force of additive technologies usage in serial production. Moreover, that would provide the opportunity to realize one more direction of Industry 4.0 in developing of distributed productions, what is being actively discussed within NTY.

Returning to the heading question: are additive technologies a miracle or a soap bubble of Fourth Industrial Revolution, I would like to say, that at the last it is just one producing technology with its cons and pros. Any way, as long as paradigm in construction will come over to a profound understanding of its process, everything becomes possible. Miracles happen to those who have intimate knowledge of the nature of things.