Ceramic-metal composites and W-base refractory alloys for applications under severe service conditions: microstructural design and alternative processing routes
Total activity: 2
Type of activity
MIN DE ECONOMIA Y COMPETITIVIDAD
Funding entity code
This project aims to develop ceramic-metal (cermets) composites and W-base refractory alloys for applications including severe service conditions. It will be done following two different approaches: optimization of microstructural design and implementation of processing routes, alternative to conventional ones. Main experimental variables to consider are chemical nature and relative amount of the constitutive phases. In the case of cermets, influence of both chemical composition of Fe-base binder (aimed to substitute reference Co) and relative concentration of TiCN and WC particles will be studied. On the other hand, the effect of adding alloy elements (Ti, Ta, Y) and presence of TiC as reinforcing phase will be investigated in W alloys. These materials have strategic application niches in diverse sectors, such as energy generation (fusion nuclear reactor), mining or aerospace (machining tools, engine and blade components, etc.). Common to all these applications is the fact that materials involved are subjected to extreme service conditions, i.e. high temperature, severe abrasion, abrupt temperature changes, and corrosion. Moreover, in agreement with social demands for sustainability, the availability of alternative materials that could be effectively considered as sustainable is requested. Within this context, main objectives throughout the project are: i) to reduce environmental impact during fabrication, ii) to enhance the performance under severe service conditions, and iii) to optimize the properties and functionality of the materials under consideration, along their (as long as possible) service lifetime. The achievement of the proposed objectives requires a multidisciplinary approach. It is here satisfied by the expertise provided by the four research groups involved in the proposal in different fields: chemistry (chemical synthesis, colloidal chemistry, corrosion and oxidation), physics (mechanics and solid state phase transformation) and engineering (processing and microstructural design of materials). This will allow to join efforts for implementing environmentally clean chemical processes as well as developing microstructural and mechanical characterization protocols, along different length scales (macro-, micro- and nano-), to assess changes induced by exposure to severe service conditions. Hence, it may be stated that the proposed project will transversally cross-link Materials Science and Engineering, from design of particles and/or composite granules, using different techniques such as chemical synthesis/reduction, dispersion and surface modification, to assessment of microstructure and mechanical integrity changes induced by high temperature exposure. In between, challenging issues such as pressing/shaping of green pieces combining colloidal and powder metallurgy techniques, sintering, and mechanical characterization of complex microstructures under quite distinct environmental conditions, will also be addressed. Furthermore, the project includes leading novelty issues in each corresponding knowledge field, such as dispersion of heavy metals, additive manufacturing of mixed suspensions of non-oxide particles, compositional and microstructural design of metallic matrices, and mechanical characterization at different dimensional scales, all together aiming to relate properties of the developed materials with the mechanical integrity and durability of the shaped components.