Netzsch (United Kingdom)

Metallic materials, predominantly steels, are the most common structural materials in the various components along the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a key factor in the ramp-up of the hydrogen economy. This requires extensive materials qualification, however, most of the accepted; and standardized test methods for determining the influence of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple, rapid, and economical method designed to overcome the limitations of the current methods for the qualification of metallic materials under high-pressure hydrogen gas. However, this technique is not yet standardized. The TransHyDE-H2Hohlzug project is presented in this article, along with the main steps required to optimize the hollow specimen technique. This includes closing knowledge gaps related to the specimen geometry, surface quality, and gas purity in dedicated working packages, thus contributing to a comprehensive standardization of the technique for tests in high-pressure hydrogen gas.Impact statementThe hydrogen economy is considered a key solution for achieving climate neutrality in Europe, as it plays a crucial role in the decarbonization of sectors such as transport, industry, power, etc. Ensuring the safety and reliability of infrastructure is crucial for the ramp-up of the hydrogen economy. Therefore, it is necessary to meticulously study the materials and components used for infrastructure under conditions that closely resemble in-service conditions. The currently standardized methods are limited as they do not precisely replicate in-service conditions, and when they do, they are often complex, costly, and not easily accessible. This article presents the hollow specimen technique, a simple, and economical method developed to address the limitations of current standardized methods. The results from this work will contribute to the standardization of this technique for tests in high-pressure hydrogen gas. This will enable a faster evaluation of materials for hydrogen applications by industry and academia, thereby contributing to the growth of the hydrogen economy.Graphical abstract

Flash methods have become one of the most commonly used techniques for measuring the thermal diffusivity and thermal conductivity of various kinds of solids and liquids such as metals, carbon materials, ceramics, and polymers. Easy sample preparation, small sample dimensions, fast measurement times, and high accuracy are only some of the advantages of this non-destructive measurement technique. However, the accuracy of measurement and level of uncertainty of the resulting data are becoming increasingly important for countless industrial applications. Instruments must be checked to determine the uncertainty of the system at different temperature and application ranges. One way of checking the accuracy of the results is to cross-check the unit with certified reference materials. However, there is a lack of standard materials for thermal diffusivity/thermal conductivity all over the world. Furthermore, for some available standards, the thermophysical properties are known only over a limited temperature range. Presented in this work are thermophysical property measurements on a certified thermal conductivity standard, Stainless Steel 310. Tests were carried out between −125 and 1000°C.

Silicon nitride based composites with different amount (1, 2 and 3 wt%) of multi-wall and single-wall carbon nanotubes, and graphene have been prepared. Optimisation of the manufacturing processes has been conducted to preserve the carbon nanotubes in composites and to avoid damaging during high temperature processing. The first results show that carbon nanotubes have a good contact to the surface of silicon nitride grains. In the case of increase of sintering pressure an increase of bending strength was achieved. It was found that microstructure features achieved by properly designed sintering parameters are the main responsible factors for the strength improvements.

The capabilities of the new NETZSCH thermo-microbalance TG 209 are illustrated by four applications from the polymer industry.