Laser facility launched for welding research

Charles T. Troy, charlie.troy@photonics.com

A new facility complete with a semi-industrial laser system has been built at the GKSS Research Center in Geesthacht, in collaboration with Airbus Deutschland GmbH. According to professor Norbert Huber, head of material mechanics at GKSS, the center has a cooperation agreement with Airbus until 2016, which allows the company to use the system for its own research and development.

GKSS has invested approximately 61 million in the facility, which was officially opened in April by representatives of GKSS and Airbus. The new system will be used to research laser welding of new lightweight construction alloys, among other areas. The materials researchers from Geesthacht are taking over the system from its Airbus location in Nordenham.

The GKSS laser welding facility combines lasers and robotics for welding lightweight materials. Image courtesy of GKSS Research Centre Geesthacht.

The new system will be used to optimize welding technologies for innovative lightweight alloys in joint research and development projects. According to Huber, the system will be welding mainly aluminum and magnesium, along with other metals and materials combinations. With the pilot system, it is now possible to weld up to a length of about 9 m in the newly constructed facility. The system employs two DC035 CO2 lasers from Rofin-Sinar with a maximum output of 3.5 kW, along with an industrial 30-kg robot arm mounted on an external 4.5-m axis from Kuka Robotics.

Focused on lightweight materials

“The system is ideal for our research in the area of strength and reliability of laser-welded lightweight structures,” said Huber, who added, “We will use the laser system for welding process development with new lightweight alloys and for producing lightweight demonstrators. Bilateral cooperations and large projects (e.g., EU) with industry are envisaged. We typically cover the process chain from fundamental research to demonstration and technology transfer.”

While investigation at Airbus in Nordenham focused on laser beam welding of length-stiffened profiles, known as stringers, for the external skin of the aluminum fuselage structure of aircraft, in Geesthacht the focus of investigation is on sample models and test components for aircraft fuselage shells.

According to GKSS, one challenge in modern aircraft and vehicle manufacture is to save cost and weight. To produce the fuselage of an aircraft, for example, laser beam welding increasingly is used as a substitute for the traditional technology of riveting. This saves weight and, along with it, carbon dioxide emissions, while reducing production time. In aircraft manufacture, strict safety regulations must be observed. Computer simulations and complicated tests are required, which include the welded seams.

Among other techniques, the materials researchers at Geesthacht use the established GKSS characterization method with neutron and synchrotron radiation for this purpose.

In the future, the GKSS Research Center increasingly will be geared toward development of new lightweight materials and material systems. To this end, construction of the pioneering GKSS Lightweight Materials Assessment, Computing and Engineering Centre (ACE) is planned. The new laser system will be part of this expansion.

The particular strength of the ACE research platform will lie in the combination of processing, characterization and simulation methods. This includes both joining technology and producing sample multimaterial systems and complex lightweight structures. As a further area of research, for example, models will be developed to enable prediction of failure behavior of such structures under loads similar to real operation.