Testing Additive Manufactured Structures for the Aerospace Industry at -269°C

Additive manufacturing methods such as laser melting afford a great amount of design freedom and therefore offer huge potential for weight minimization. Due to the typically small quantities in aerospace this manufacturing method can also be implemented cost-effectively. KRP Mechatec relies on a testing machine from Zwick Roell for testing additive manufactured aluminum and titanium structures at low temperatures down to -269°C .
compression test kit

Cyrostat installed in an AllroundLine (Source: KRP Mechatec)

KRP Mechatec, located in Garching, Germany near Munich, specializes in the development and analysis of materials and structures for the aerospace industry. In aerospace (for example for launch vehicles), liquid hydrogen (-253°C or .20 K) is used as fuel. Their tanks are subjected to extremely high loads during take-off at these low temperatures. The objective of the test program at KRP is to maximize the potential of lightweight construction for additive manufacturing also for this special application. Material specimens are manufactured from the aluminum and titanium alloys used and tested in an individual test arrangement. The company uses a materials testing machine (Fmax 250 kN) from Zwick Roell.

For the AllroundLine Z250SW, KRP developed and commissioned a special fixture, which allows various materials tests including tensile, compression, shear, and hole widening tests to be performed in a cryostat. In the cryostat, the specimens and arrangement are cooled to -196°C using liquid nitrogen and to -269°C using liquid helium and then tested at that temperature.

Dr. Ing. Christoph Zauner, Technical Manager at KRP Mechatec explains the decision to partner with Zwick Roell: "Zwick Roell provides us with the support we need to perform our special test tasks. The testing machine and the software afford us flexible implementation in our research and development."