Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser Welding of large Format Metal-Foam Sandwich Materials

20.04.2012
Scientists at the Laser Zentrum Hannover have developed a process for laser welding large scale, metal-foam sandwich materials, in which intermetallic phases do not occur. The project MESCHLAS aims at providing lightweight construction using sandwich technology, including the processing necessary to accomplish this.

Promising results for lightweight shipbuilding constructions: The Laser Zentrum Hannover e.V. (LZH) and project partners have laser welded a demonstrator for marine gear unit foundations made of steel and aluminum foam sandwich material. The LZH will present results at the Hannover Messe 2012, from April 23rd to 27th.


Laser fillet weld support (LZH)

Metal foams are highly porous, lightweight materials which, due to their cellular structure, can absorb energy in the form of vibrations and knocks, or noise. They are also heat resistant and provide insulation against electromagnetic waves. Metal foams, embedded in so-called sandwich constructions with aluminum or steel sheets, have a much higher bending stiffness than solid sheets, and due to their lower weight, are especially suitable for lightweight construction, or for highly stressed parts.

Large scale metal-foam sandwich materials are especially interesting for highly stressed ship structures such as foundations for machines, or for rudder structures, since weight reduction up to 20 % is possible. However, steel-aluminum lightweight structures are difficult to weld, due to inhomogeneity of the foam core, high stiffness, and the material thicknesses. One problem is, for example, the thermal effects of foaming the aluminum core in mixed sandwich materials, which can distort the material. Welding can also lead to intermetallic phases, causing cracks in the welding seam.

Scientists in the group “Joining and Cutting of Metals” have developed a process for laser welding large scale, metal-foam sandwich materials, in which intermetallic phases do not occur. Their investigations are in the framework of the joint project MESCHLAS. This process was recently tested on a gear unit foundation at Blohm + Voss Naval GmbH in Emden. It uses a transportable axis system and a mobile diode laser, which were provided by the companies Scientific and Efficient Technologies Ltd. (SET) und LASER on demand GmbH (LoD).

As the first step, mechanical preparation of the panel edges is necessary.

The aluminum foam which adheres to the steel top sheets (S235JR) is removed, thus preventing intermetallic phases. Then the components must be exactly positioned, forming a zero gap. Due to the size of the panels, this step is rather challenging. Following this, the sandwich panels are fixed using conventional spot welding. Laser welding of the butt welds and fillet welds then takes place, using a diode laser with a wavelength between 900 and 1030 nm and an output of 5 kW. Tests show that a gap of 0.6 mm can be bridged, and continuous weld seams are possible. Depending on the material thickness (up to 5 mm), speeds of 0.2 to 1.5 m/min. were possible.

The project MESCHLAS aims at providing lightweight construction using sandwich technology, including the processing necessary to accomplish this. The LZH is working together with the Fraunhofer Institute for Machine Tools and Forming Technology (IWU) and the companies Blohm + Voss Naval GmbH and Precitec Optronik GmbH to accomplish this goal. The project is financially supported by the Federal Ministry of Economics and Technology, based on a decision made by the German Parliament.

Be sure to visit us during the Hannover Messe, hall 17, stand C 55!

Contact:
Laser Zentrum Hannover e.V.
Michael Botts
Hollerithallee 8
D-30419 Hannover, Germany
Tel.: +49 511 2788-151
Fax: +49 511 2788-100
E-Mail: m.botts@lzh.de

The Laser Zentrum Hannover e.V. (LZH) carries out research and development in the field of laser technology and is supported by the Ministry of Economic Affairs, Labour and Transport of the State of Lower Saxony (Niedersächsisches Ministerium für Wirtschaft, Arbeit und Verkehr).

Michael Botts | idw
Further information:
http://www.lzh.de

More articles from Trade Fair News:

nachricht Fraunhofer HHI at Mobile World Congress with VR and 5G technologies
24.02.2017 | Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut, HHI

nachricht MWC 2017: 5G Capital Berlin
24.02.2017 | FOKUS - Fraunhofer-Institut für Offene Kommunikationssysteme

All articles from Trade Fair News >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>