Deliverable 3.1 [Thermomechanical properties: Process/microstructure/properties relationship]

This deliverable collects the activity performed in the first two years of the project in the frame of WP3 - Task 3.1 and presents the thermo-mechanical characterization of the UHTCMCs produced and extensively described in Deliverable 2.1. The overall objectives of WP3 include: -creation of a database containing the full set of thermo-mechanical properties; -determination of the self-healing capability (expected in Deliverable 3.2, M30); -validation of prototypes developed in TRL4 through environment-centred tests (expected in Deliverable 3.4 and 3.6, M30); -development of analytical and numerical macro-models to predict the material stability (expected in Deliverable 3.8, M40); -understanding of aging mechanisms through atomistic modelling (expected in Deliverable 3.9, M36). Accordingly, this Deliverable 3.1 accomplishes the first of the above objectives. The thermo-mechanical characterization of the new UHTCMCs is one of the key issues to assess the potential use of these materials in harsh environments, therefore it is extremely important to have an overview of the new materials performances and the possibility to compare them to those of other state of the art materials, conventional CMCs and UHTCs. The first part of this task was dedicated to identify the reference standard procedures and potential lack of the same. After review of the existing documents, it seems clear that there is still need of standards to cover important aspects related to the mechanical characterization of CMCs with continues fibers. Upon homogenization of the testing methods and specimens features (size, surface finishing, etc.) among the partners, the most promising materials have been tested from room temperature (RT) and up to 1500°C and, for selected compositions, even up to 1800°C. Tests at 2000°C will be performed in the final stage of the activity on materials selected for the scale-up in WP4. The following mechanical properties have been evaluated: -hardness (RT); -Young's modulus (RT); -flexural strength (RT-1800°C, Ar); -fracture toughness (RT-1500°C, Ar); -tensile strength (RT); -interlaminar shear strength (RT). As for the thermal properties, we focused on: -thermal shock resistance; -thermal conductivity up to 2000°C; -thermal expansion coefficient up to 1500°C. The output collected within this deliverable served as inputs for deliverable 2.6 submitted on M20, which preliminary assessed the most promising processing routes for application 1 and 2.