Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fine-tuning for additive production

15.11.2019

"COAXshield" and "LIsec": Fraunhofer IWS presents shielding gas nozzle and light scanner for laser powder build-up welding at "formnext" trade fair

Additive manufacturing systems can generate highly complex components, which could not be produced with conventional machine tools or only with great effort. Nevertheless, such industrial 3D printers are far from being standard equipment in factories.


“COAXshield” – novel local shielding nozzle system for laser metal deposition applications with sensitive materials

© Fraunhofer IWS Dresden


The measuring device developed at Fraunhofer IWS allows significantly simplified quality control and provides conclusions about the wear degree of the powder nozzle.

© Fraunhofer IWS Dresden

This is not just due to the purchase costs, but also to many other challenges. The Fraunhofer Institute for Material and Beam Technology IWS Dresden has developed particular solutions and will present them at the "formnext" trade fair in Frankfurt am Main in November 2019.

Included here are “COAXshield”, a local molten pool shield for laser powder build-up welding and the “LIsec” analysis device for controlling the powder flow in additive manufacturing processes.

Titanium, a material popular in aerospace, oxidizes in contact with air at processing temperatures above or equal to 300 degrees Celsius. As a result, the material properties change. The components become brittle and can crack. If, for example, a laser is used by a robot to manufacture a titanium workpiece additively, a large chamber must be built first around the robot and the component.

This chamber is then either flooded with a low-reaction noble gas such as helium or argon or a vacuum must be generated before manufacturing can start.

“This kind of process shielding may be suitable for small component sizes, but it causes considerable difficulties for the production of large components in terms of process control and accessibility,” explains Jakob Schneider, who focusses his research on additive manufacturing at Fraunhofer IWS.

“In addition, the costs for such a chamber increase proportionally with the size of the component to be protected. These are, for example, the expanses for several cubic meters of helium or argon, which may also have to be pumped in and out due to intermediate processing steps.” The same applies to workpieces made of further materials, so-called “refractory metals”, such as tantalum, niobium or titanium-aluminum compounds.

“COAXshield” protects titanium components

For this reason the IWS has developed “COAXshield”, an alternative protective shield designed to direct the shielding gas only to the areas where it is really needed: directly around the laser beam's processing zone, which melts the metal powder and deposits it layer by layer on the component. The nozzle head can be mounted under standard processing optics. It encloses the powder nozzle and forms a protective gas cone “coaxially” around the process zone.

This cone thus only protects the hot processing zone, because just here titanium and ambient air can react with each other.

“This solution saves the user a lot of time and money,” emphasizes Jakob Schneider. “In addition, very large titanium components can also be additively manufactured.”

An example: For the X-ray space telescope “ATHENA”, the European Space Agency ESA needs a satellite supporting structure made of titanium with a diameter of several meters. In cooperation with Fraunhofer IWS, ESA is developing a process and the associated system technology for additive manufacturing. The “COAXshield” has been developed in this context .The technology is expected to be ready for the market at the beginning of 2020.

“LIsec” lights the powder stream

While in conventionally used ablative processes such as milling, the calibration of the tools corresponds to the state of the art, in laser powder build-up welding it is still a great challenge. The “LIsec” measuring device was developed at the IWS to solve this challenge and move the limits to technical feasibility. The abbreviation stands for “Light Section” and reveals the principle: A measuring laser scans the powder flow after leaving the nozzle.

A right-angle camera is mounted, which records light sections through the powder and forwards them to analysis software. “The three-dimensional distribution of the powder stream can be calculated with high precision,” explains IWS engineer Rico Hemschik. “This allows significantly simplified quality control and provides conclusions about the wear degree of the powder nozzle.”

For example, it can be used to repair damaged or worn turbine blades on aircraft in a higher quality and more reliably than before. “In this respect, our measuring device can contribute to greater safety and lower maintenance costs in aviation,” says the IWS engineer. The Dresden Institute is already working on the industrial implementation of the technology with several well-known international companies and research institutes.

VISIT US @FORMNEXT 2019
Fraunhofer IWS will be present at formnext 2019, from November 19 to 22 at Hall 11.0, booth D51 (Fraunhofer). Feel free to stop by.
More info: https://www.iws.fraunhofer.de/en/trade_fairs/formnext_2019.html

Wissenschaftliche Ansprechpartner:

Dr. Elena Lopez
Head of department Materials and Failure Analysis
Fraunhofer Institute for Material and Beam Technology IWS
Winterbergstraße 28, 01277 Dresden
elena.lopez@iws.fraunhofer.de
Phone +49 351 83391-3296

www.iws.fraunhofer.de 

Originalpublikation:

https://www.iws.fraunhofer.de/en/pressandmedia/press_releases/2019/presseinforma...

Markus Forytta | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

More articles from Machine Engineering:

nachricht Efficient engine production with the latest generation of the LZH IBK
13.11.2019 | Laser Zentrum Hannover e.V.

nachricht Magnets for the second dimension
12.11.2019 | ETH Zurich

All articles from Machine Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...

Im Focus: Developing a digital twin

University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making

In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

City research draws on Formula 1 technology for the construction of skyscrapers

10.12.2019 | Architecture and Construction

Reorganizing a computer chip: Transistors can now both process and store information

10.12.2019 | Information Technology

Could dark carbon be hiding the true scale of ocean 'dead zones'?

10.12.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>