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.
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!
Michael Botts | idw
Plastic Optics from Aachen at Fakuma 2018
08.10.2018 | Fraunhofer-Institut für Produktionstechnologie IPT
New enclosure gives a boost to electrical engineering companies
26.09.2018 | Rittal GmbH & Co. KG
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time
The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...
02.10.2018 | Event News
01.10.2018 | Event News
21.09.2018 | Event News
15.10.2018 | Physics and Astronomy
15.10.2018 | Life Sciences
15.10.2018 | Life Sciences