NFDI-MatWerk/IUC02 Data schema for elevated temperature tensile data of Ni-based superalloys

Strength characteristics, such as proof strength and tensile strength, of metallic materials are usually measured at room temperature. However, for high-temperature materials, the values at operational temperatures are equally important for analyzing the mechanical behavior of components [1] or for designing purposes. Elevated temperature tensile tests (often referred to as hot tensile tests) generally enable the measurement of the same material parameters as those obtained at room temperature [1]. Typically, tensile and proof strength, elongation after fracture, and reduction of area are analyzed, with the focus often being on proof strength [1].

The attached data schema for elevated temperature tensile tests was developed within the German NFDI-MatWerk initiative (https://nfdi-matwerk.de/). It builds on the previously published creep data schema [2] and follows the reference data methodology outlined in [3]. Please consider citing this work [3] if you use the data schema for a scientific publication.

The presented schema constitutes a structured approach for collecting all relevant information on an elevated temperature tensile test experiment. Overall, this development, as defined in the previously published data schema for creep data [2], aims to provide a comprehensive hierarchical data description that can be implemented in data management platforms (such as electronic laboratory notebooks), facilitate consistent quality assessment across different users and data providers, and promote the alignment of datasets to the FAIR principles by providing easy interoperability and full reusability.

The presented schema was initially developed for datasets of Ni-based high-temperature alloys. However, thanks to its modular structure, it can also be applied to tensile tests of various metallic and other materials. Although the focus is on elevated temperature tensile testing, the data schema also offers a solid foundation for documenting room temperature tensile tests. In such cases, an adjustment of the requirement profile might be necessary, and categories or entries specific to mechanical testing at elevated temperatures, such as “temperature-measuring system”, “specified temperature”, or “soaking time”, become irrelevant.

Overall, a detailed approach was followed to ensure the collection of all relevant information, including both metadata and test results. This includes, for example, comprehensive descriptions of the material’s manufacturing history and of the laboratory equipment, and basic strength and deformation characteristic values. The resulting data schema aims to support the description and identification of high-quality datasets, which may qualify as reference data of materials. Our current definition of reference data of materials is available in [4]. It should be noted, however, that not all research datasets —depending on their origin and purpose— require this full level of detail. Nevertheless, the presented data schema can support data providers in evaluating the completeness and value of their datasets.

This version of the data schema covers elevated temperature tensile tests on both single- and polycrystalline specimen materials. The terminology is aligned with DIN EN ISO 6892-1 and DIN EN ISO 6892-2 [4,5]. It is designed to record the use of temperature measurement using thermocouples and the use of contacting extensometer systems.

The data schema is provided in XLSX and CSV formats. It comprises 11 columns. The columns labeled as “Category I” to “Category IV” define the overarching structure of the schema (see Figure 1) and reflect how a domain expert would logically organize the information. The subsequent columns “Entry”, “Symbol”, “Data Type”, and “Exemplary Answer or Options Separated by Slash in Case of Data Type Drop-Down List” specify the fields to be completed by the user. Where applicable, standard-compliant symbols and community-common units are provided. The columns “Data Type” and “Exemplary Answer or Options Separated by Slash in Case of Data Type Drop-Down List” offer initial guidance on how each field should be populated; most entries include exemplary answers. For fields defined as “drop-down list”, the selectable options are indicated in the format “Option A / Option B / …”. The column labeled “Requirement” presents the requirement profile, while the final column, “Comments”, provides additional explanations related to requirements, dependencies, and the applicability of specific entries.

The requirement profile refers to the highest quality class of reference data, taken from calibrated instruments, and which shall enable the following usages:

1.      Checking one's own elevated temperature tensile test results on nominally similar material

2.      Verification of own testing set-up (e.g., by testing the same or a similar material)

3.      Using the data as input data for simulations in the context of design or alloy development

References

[1] B. Skrotzki, J. Olbricht, H.-J. Kühn, High Temperature Mechanical Testing of Metals, in: S. Schmauder, C.-S. Chen, K.K. Chawla, N. Chawla, W. Chen, Y. Kagawa (Eds.), Handbook of Mechanics of Materials, Springer Singapore, Singapore, 2018, pp. 1–38.

[2] Ávila Calderón, L. A., Shakeel, Y., Schriever, S., Gedsun, A., Forti, M., Jordan, H., Han, Y., Baer, O., Aversa, R., Olbricht, J., Hammerschmidt, T., Hickel, T., Skrotzki, B. (2024). NFDI-MatWerk/IUC02 Data schema for creep data of Ni-based superalloys including a comprehensive documentation of test results and metadata (1.1). Zenodo. https://doi.org/10.5281/zenodo.13820070

[3] L.A. Ávila Calderón, Y. Shakeel, A. Gedsun, M. Forti, S. Hunke, Y. Han, T. Hammerschmidt, R. Aversa, J. Olbricht, M. Chmielowski, R. Stotzka, E. Bitzek, T. Hickel, B. Skrotzki, Management of reference data in materials science and engineering exemplified for creep data of a single-crystalline Ni-based superalloy, Acta Materialia 286 (2025) 120735, DOI: 10.1016/j.actamat.2025.120735

[4] Hickel, T., Richter, S., Bitzek, E., Ávila Calderón, L. A., Gedsun, A., Forti, M., Hammerschmidt, T., Olbricht, J., Skrotzki, B. (2024). NFDI-MatWerk/IUC02 Definition for Reference Data of Materials (1.0). Zenodo. https://doi.org/10.5281/zenodo.11667673

[4] DIN EN ISO 6892-1:2020-06 Metallic materials - Tensile testing Part 1: Methode of test at room temperature, Deutsches Institut für Normung e. V. (DIN), Beuth Verlag, Berlin, 2017.

[5] DIN EN ISO 6892-2: 2018-09 Metallic materials - Tensile testing - Part 2: Methode of test at elevated temperature, Deutsches Institut für Normung e. V. (DIN), Beuth Verlag, Berlin, 2018.

Acknowledgment

This work was carried out in the framework of NFDI-MatWerk and funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under the National Research Data Infrastructure – NFDI 38/1 – project number 460247524.