German exploration of laser welding in microgravity

From June 21 to 23, lasys, the annual international laser material processing exhibition in Stuttgart, Germany, will be held grandly. It is reported that in this grand event, the German Hannover Laser Center (lzh) will show its progress in the field of lightweight manufacturing and its latest innovations in systems and technologies.

In addition, lzh will also show the laser material processing process using the selected laser processing head, as well as the independent and complete solution of the system. According to reports, they use a modular and controllable laser head for connecting plastic.

The Hannover laser center in Germany is developing a series of innovative production methods. The picture shows the laser head used for coaxial deposition welding. (image source: lzh)

Another focus is the potential of intelligent additive laser manufacturing. It is reported that lzh will also show how the future intelligent agricultural technology will operate and play a role. Specifically, they will demonstrate a laser based, sustainable, herbicide free weed control process.

In the two lectures during the exhibition, lzh scientists will discuss the latest progress in laser based glass additive manufacturing. In addition, Wissenschaftliche Gesellschaft Lasertechnik (WLT) and its members and industry partners have held lectures on the current trends in the field of laser material processing.

Lzh exploring space laser welding

Lzh scientists are studying the effect of gravity on the laser welding process. The experiment conducted with Einstein elevator of Leibniz Hannover University (Luh) is expected to bring a series of key new insights.

At present, in order to equip the space station, the fully assembled components must be transported to space. This takes up the cargo hold and brings high fuel costs. To solve this problem, laser welding is a potential ideal solution, which can directly connect additional parts or spare parts together on site. The lzh team said that the existing equipment can be flexibly expanded, modified or repaired, rather than replacing the entire component.

Welding experiments were carried out in Einstein elevator of Hannover University in Leibniz under microgravity. (image source: Luh)

Many conditions of laser welding in space are different from those on earth. In addition, vacuum conditions, radiation, electric and magnetic fields can also lead to differences in the performance of materials and processes (such as laser welding).

How does gravity affect the molten pool? This is the problem that researchers want to study in Einstein elevator. According to the project that lzh team is working on, they are planning to apply similar / different joints made of aluminum alloy and steel materials to the flow behavior caused by laser welding. For different welding schemes, scientists also want to analyze the mixing behavior of materials in the melt. In addition, they will also study the effect of convection on the molten pool and the resulting joint under microgravity conditions.

Lzh's Einstein elevator experiment is a further development of the classical falling tower theory. This kind of experiment can be carried out in the environment of weightlessness and microgravity (about corresponding to weightlessness). It is reported that the microgravity that can be achieved in the experiment is less than 10-6g, and the maximum duration of the experiment is 4 seconds. In the absence of vacuum, Einstein's elevator can reach a microgravity value of 10-4 grams - a condition corresponding to the conditions of the international space station (ISS).

Source: OFweek