Mechanical Testing of 3D-printed High Performance Thermoplastics for Cryogenic Applications: Evaluation of Processing Parameters and Test Set-Up

In recent years, socioeconomic trends drive research aimed at establishing hydrogen as a clean energy source. Especially the decarbonization of travel presents itself as a vital aspect of this development. However, integrating hydrogen into weight sensitive applications such as aircraft presents unique challenges including proposed weight gains and limited storage space, with liquid hydrogen taking up several times more volume than kerosene. These challenges may be resolved through utilization of modern manufacturing techniques, including additive manufacturing and use of high-performance materials. Selecting materials able to withstand the harsh hydrogen environment and extreme cold temperatures associated with its liquid storage is critical. In general, materials tend to embrittle as the temperature drops. Furthermore, many traditional metals suffer from additional hydrogen-embrittlement, making them unsuitable for hydrogen infrastructure. In contrast, high-performance thermoplastics offer resilient alternatives to hydrogen and exhibit promising mechanical behavior at low temperatures. However, testing mechanical behavior of additively manufactured samples at cryogenic temperatures requires a non-standardized setup and often yields unreliable data. Furthermore, the printing process heavily influences material properties. This paper aims to evaluate a selection of parameters focusing on interlayer bonding to provide more reliable fracture data and proposes a setup for the evaluation of cryogenic material behavior.