ASSISTENSE

The evolution of techniques and processes in many industries, particularly in the nuclear sector led to the fact that the materials may be required to work under more severe conditions. Thus, specific developments in nuclear applications in particular, including degraded or accidental modes, can lead to innovative solutions in terms of generic processes and materials resistant to severe loads in extreme environments. Among these materials, composites can find applications in all sectors (energy, environment, aeronautics, chemistry, etc ...). In this context, problems concerning assembly in general and that of high performance composites in particular is an important issue with generic characters for strategic applications in the fields, for example, energy, chemistry or pharmacy. Thus, the ASSISTENSE project proposes to develop, evaluate and transfer one or more innovative (s) method (s) for assembly of composite materials. This hybrid process is based on the dry deposition (PVD or projection) of a brazing material followed by the assembly phase itself. The project builds on the three aspects development / process - physicochemical characterization - assemblies' performances of the obtained componants. Relations that link these three aspects must be able to respond to certain limitations of conventional assembly methods. Objective of the ASSISTENSE project is to lead to a breakthrough in terms of processes and materials in the assembly of high performance composites for extreme environments. More specifically, it is part of applications for development of the GFR and sodium nuclear reactor. It will also allow progresses in many fields such as nuclear energy (fuel cladding, thermonuclear fusion), or for aerospace applications (rear engine body composite nozzles or ejection It will also allow development of high performance compact heat exchangers which can operate at high temperature (heat exchanger in the field of energy recovery) and / or in harsh environments (heat exchanger reactor for chemicals and pharmaceuticals). The ASSISTENSE project revolves around two main work packages, development of process for depositing the brazing material by dry process (PVD or projection) associated with the development of the assembly process. This should allow one hand to reduce costs of implementation of the solder and also be able to ensure a homogeneous distribution of the solder at any point of the component and thereby obtain enhanced mechanical properties. Upstream, two lots of work must be supplied, as output data, a specification of the brazing material in relation with application and delivery of this material in powder form compatible with the projection and as a source compatible with magnetron sputtering technology. A lot of work is entirely devoted to the physicochemical characterization of surfaces and interfaces. Downstream, two batches of work are primarily focused on achieving demonstrators and evaluation, and then on the valuation and transfer study of process(es). Regarding these last two batches, ASSISTENSE is a collaborative project for which the industrial partners are involved in all stages of development, in order to optimize stages of demonstration and transfer.