Stefan Ritt, vice president, Global Marketing and Communications (Lübeck, Germany; Wixom, MI), is a recognized leader and expert in AM metals business and applications. Stefan travels in all of markets of the world including North America, South America, Africa, Europe, and Asia. He has seen current metal additive manufacturing (AM) applications and developments giving him a unique perspective on this market and where it is going. I sat down with Stefan to take a look at the metal AM market from a global perspective.
Manufacturing Engineering: Stefan, you have been in manufacturing your whole career as well as at the beginning of additive manufacturing (AM). Is additive manufacturing becoming part of the whole picture of manufacturing?
Stefan Ritt: Yes, absolutely! Approximately 10 years after the market first saw the performance of metal AM-machines, we all can see real industrial applications happening. Dental caps and crowns have been the first mass-produced articles in this respect for many years. Now aerospace companies are making firm plans for AM factories around the globe for the coming years.
Industrial use of metal AM is actually happening now.
ME: Is AM in metals being implemented as a manufacturing method in Europe as well as Asia?
Ritt: With metal AM being a European invention from the mid-1990s, it is natural that we have seen the first applications with the European industry. However, the US has picked up very fast and we can see how seriously from the example of GE’s bid for our company last October which was for more than the amount of €700 million [approximately $745 million]. China has started a significant program for its own aerospace engine development last year and we do see a lot of Chinese metal AM machines coming to the market since then. Singapore has funded the development of this industry for many years and has established a very nice and competent infrastructure at their universities. Also, Russia has identified this technology as one of the key research areas and wants to produce its own intellectual properties there.
Except Africa at the moment, we can see a global movement which becomes more professional and solid every month.
ME: What are the main issues in metal AM when being used for production?
Ritt: One of my favorite quotes is that we all in this industry started to produce cars without thinking about driving schools and gasoline stations! This picture should point to the fact that thinking and education in freeform design and AM-friendly production, as well as the sufficient supply of metal powders, are key aspects needed to bring this technology to maturity.
Furthermore, the integration of metal AM machines into the total production flow will need expertise and consulting to be built up in due course to achieve well-functioning work environments.
ME: For what applications are being used in AM metals today?
Ritt: From our point of view, the main requests are coming from industries which need highly complex, bionic structured, and lightweight parts. This does apply mainly to aerospace, energy, medical implants, dental, and also partly for automotive industries.
ME: There are different AM metal processes, which one currently holds the most promise for manufacturing?
Ritt: From discussions with many potential customers, the powder bed fusion with lasers is the most accurate, controllable, and predictable process and therefore the industries referred to above concentrate on it. For bigger parts, the supply of material per time unit is asking for adaptations like wire feed, and first testing apparatuses are designed to verify that approach.
For certain big and individual parts, production powder-nozzle systems like DMD or LENS are used, but those suffer from a few headaches like low density, high stress potential, and problems with powder recycling.
ME: What peripheral technologies need to be adapted to make AM metals more viable for manufacturing?
Ritt: The metal-AM process does produce a fully dense but relatively inaccurate and rough surface raw part. Therefore, surface treatment and machining for accuracy as well as heat treatment to avoid stresses have to be adopted and designed in line with the Selective Laser Melting process.
Also, powder handling and recycling, as well as support removal, need more automation in the process. This is being worked on at the moment with various concepts by the manufacturers.
ME: Can you comment on how many different metals and metal alloys are out there now being used in AM machines? I hear that ceramics are now being combined with metals in AM. Is there a market for multi-material combinations?
Ritt: The powder bed fusion process is able to process all weldable metals (also combinations of them!) in theory.
In the practical world out there, approximately 30-plus metals have been qualified for everyday use with the systems. Principally, aluminum, titanium and various steels and their alloys are used. High chromium and nickel alloyed steels like Inconel are used for turbine blade applications.
Also precious metals like gold, silver, and platinum are used specifically for jewelry applications.
Copper use is being developed at the moment in various university projects.
We do know of a titanium-zirconium-mix application for medical purposes and have seen aluminum oxide and silizium carbide tests for dental applications. However, those ceramics mix applications often suffer cracks from the high cooling-down gradient of the process and will require higher pre-heating within the process. This is being worked on in research right now. Also the first silizium oxide applications have come up for glass and received patents recently.
Many years ago, we tried multi-material feed in a few machines for scientific applications. This did not go very far at that time because of the limited adjustments, handling of powders in the process, and waste of all used material due to the mixing during the process.
For example, we do see requests for copper combined with other materials to establish conductive areas in non-conductive environment of parts. Whether this is for electrical or heat conductivity, both were requested.
ME: Where do you see this technology going 10 years from now?
Ritt: For sure, we will see well-established production of specialized parts in factory environment everywhere as “the usual thing” in 10 years.
We will also have this technology as part of every engineer’s and designer’s education at universities around the globe.
It is a very exciting and fast development and this is why we did form the slogan “Future Manufacturing Now!”
We all are right in the middle of a significant change of the way how we will manufacture goods and parts in the future.
After earning his engineering diploma in technical physics in 1985, Stefan Ritt started his career as prototype shop manager of a midsize Dutch-German manufacturer of vending equipment, which later was owned by a Danish group. Since 1998, he has been the international export sales and marketing manager for the SLM Solutions Group, a midsize manufacturer of RP tooling and prototyping equipment as well as the latest AM technology 3D printers for metals. Ritt is responsible for building a global network of distributors and subsidiaries in more than 30 countries and is currently the VP, Global Marketing and Communications.
In addition to his main responsibilities, he was appointed to be the global ambassador of the AMUG (Additive Manufacturing User Group) as well as international adviser to SME. He also serves as chairman of the DIN-ISO standardization work groups for additive manufacturing. Ritt is appointed guest lecturer for international business communications at the Technical University of Hamburg and serves as technical expert at the European Parliament in Brussels and for CECIMO, the European toolmakers association.
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