Materials Development through Creep Tests up to 1,600°C with the Kappa Series from ZwickRoell at the Institute of Physics of Materials (IPM)

With the goal of expanding operating temperatures and achieving a reliable assertion for the life of the creep applications through basic research, experts at IPM are examining future-oriented materials for their creep properties. Research activities are focused on ODS alloys, nickel-/cobalt-based super alloys, molybdenum disilicide, and the latest generation of high-temperature resistant steels. The performed creep tests are based on common standards such as ISO 204. However, for research purposes, non-standardized tests are also performed, for example, on atypical specimen sizes and shapes.

In particular, the three research groups “Advanced High-temperature Materials”, "Brittle Fracture" and “Advanced Metallic Materials and Metal Based Composites” are concerned with investigating the high-temperature resistance during creep and fracture testing. Therefore, there are nearly 40 creep testing machines from various manufacturers in IPMs laboratories. The three ZwickRoell creep testing machines from the Kappa LA and Kappa SS-CF series, all equipped with vacuum chambers, cover the complex creep and fractrure tests with test temperatures up to 1,600°C in an inert gas atmosphere or vacuum.

The high demands that are placed on the material are reflected in the demands of the materials testing systems. With the procurement of each individual testing machine for expanded creep and fracture tests up to 1,600°C, IPM was required to make an open bid invitation. ZwickRoell won in the end, not only due to the positive experiences that IPM already had using ZwickRoell materials testing machines, but also due to the technical specifications when compared to the competition.

At the same time, reaching the required temperatures up to 1,600 °C in an argon inert gas atmosphere within a vacuum chamber played a large role in winning the bid, as did the precise and constant temperature, force, and strain control as well as standard-compliant axial alignment.

Due to being equipped with the respective high-temperature resistant tools, tensile as well as compression tests can be performed with the ZwickRoell creep testing machines. The ease with which tools can be changed and the interchangeability between the testing machines provide IPM another benefit. Using a high-temperature resistant extensometer, the strains are measured directly on the specimen with a resolution of 0.1 µm.