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Wire-based Laser Metal Deposition (LMD-W) of Titanium Grade 5

Poster presented at 10th International Laser Symposium & International Symposium »Tailored Joining«, February 27 - 28, 2018, International Congress Center Dresden
 
: Schulz, Martin

:
Poster urn:nbn:de:0011-n-4944029 (254 KByte PDF)
MD5 Fingerprint: 79c8d0d32297c4373d1667caca53296f
Erstellt am: 29.5.2018


2018, 1 Folie
International Laser Symposium <10, 2018, Dresden>
International Symposium "Tailored Joining" <2018, Dresden>
Englisch
Poster, Elektronische Publikation
Fraunhofer IPT ()
Lasermaterialbearbeitung; Titan

Abstract
Titanium is an outstanding lightweight metal, which has a lot astonishing properties. However, there are some restriction limiting the usage. As an example melting titanium is energy consuming and expensive. That is why titanium usually is only used were the price of the material is less important than other characteristics, for instance the weight in aviation. In these applications, not only the density of the material is an important factor, but also the total weight. Therefore, a lot of material volume is often removed while manufacturing parts to get a lattice framework reducing the weight. In the case of titanium, this operation, which contains usually a milling process, is especially laborious and cost intensive. Thereby, the already expensive raw material is machined extensively, making the final part even more expensive. [1,2] Additive manufacturing is one way to overcome this drawback by near-net-shape manufacturing. While selective laser melting (SLM) only allows the manufacturing of small parts, laser metal deposition (LMD) also allows the manufacturing of parts of several meters. While processing titanium by wire-based LMD, oxidation is one of the main challenges. [3] Usually oxidation is avoided by filling the whole process chamber with argon or even applying vacuum, which is expensive and time consuming. Therefore Fraunhofer IPT realized an adapted local shielding gas concept for wire-based laser metal deposition of titanium grade 5. The process has been optimized by reducing the heat affected zone and therefore the area, which has to be coved by shielding gas. Additionally the shielding gas concept can be monitored and adapted using a streak camera. It has been already confirmed that the gas nozzle should be as symmetrical and sharp edged as possible to avoid the formation of vortexes. A higher gas volume flow also results in a higher impulse, creating a more efficient shielding on the one hand, while very high impulses can irritate the melting pool on the other. Finally, the capability of the process was shown by building up demonstrator parts. Tensile specimens, which were manufactured out of titanium grade 5, showed characteristics comparable to subtractive manufactured parts of titanium grade 5. The Fraunhofer IPT demonstrated that it is possible to build-up parts made out of titanium grade 5 with a local shielding gas concept using wire-based LMD. Thereby, the process shows the potential to produce structural parts for aviation.

: http://publica.fraunhofer.de/dokumente/N-494402.html