MAY - 20219MANUFACTURING TECHNOLOGY INSIGHTSprocessing. What is hindering a mass production?Achilles heel of polymers are temperature and creep resistance. Plus having a good thermal conductivity makes metals the selected material for combustion engines. However, selective laser sintering (SLS), selective laser melting(SLM) or binder jetting (BJ) starting from metal powders are relatively new and lack validation under fatigue load at elevated temperatures. Additive Manufacturing of metals on the way to serial productionAlike any new technology when entering its market, AM starts, were small lot sizes are required. How small is small? Once the digital dataset is generated a lot size =1 is possible. That was the go for individualized personal dental applications. For an engine maker it means: We are ready to market on spare parts, cutting storage costs for parts and molds, and opening JIT-availability worldwide without transport. With this experience the market will open for customer driven individual adaptions to our standard power units.There are manifold options of further optimization, as can be seen from the spare part shown. SLM-printed to save a molding tool, the airduct fits for purpose. However, micrographs reveal a heterogenic layered structure resulting from melting seam of the laser and a high ratio of pores. How can a printed spare part comply with the requirements then? Since the low-cost aluminum-alloy AlSiCu3 had to be replaced with AlSi10Mg for availability, the imperfections are overcompensated by a doubled fracture strength.The example not only showspotential to optimize function and costs (AM-compatible redesign with reduced wall-thickness based on FEA, finer and slower SLM, post-homogenizing heat treatment, development of low-cost raw materials). Not being able to envision the full scale of this very versatile technology we here barely "copy the design of the past".Why not investigate the "toolbox of developments" to enlighten the future?Advanced materials for Additive Manufacturing to comeAs well starting from powders ceramics are coming into focus next. Imagine we would send a robotic printer to Mars which uses nothing else than lenses and pure sunlight to melt marsian sand according transmitted design data. Will it be possible to build shelters for astronauts before arrival? Together with Royal Colage of Art, London the product designer Markus Kayser has successfully AM-manufactured sculptures from Sahara sands, achieving some 2.000°C from sunlight with his equipment. Did you recognize? Another barricade is breaking: Limits in size!What if we lay our material norms into the drawer and ask ourselves: What new type materials compositions make AM-techniques possible?Where brittleness is a weakness of ceramics, their toughness increases with decreasing grain size. Using LED-light and a fine Silicium-Carbide-powder can beAMedto a green compaction. By a thermal post-treatment, a fine grained polycrystalline and thus tough SiC is backed, achieving a performance near to Diamond. Similar for nanoscale Yttriumoxids (Y2O2).Why not taking advantage from the melting and cooling cycles following the laser beam to modify the structure of materials? Fraunhofer - and Max-Planck-Gesellschaft have lifted the hardness of "Maraging Steels" by 50% by thermally influencing the intermetallic phases. And AM is the only technique ever to consolidate metallic gears in amorphous (= non-crystalline) state by fast cooling.Summarizing for Deutz AG, AM bears a great outlook to meet our demand for durable components at high temperatures.
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