Ultrafine-grained materials processed by fast Dynamic Plastic Deformation – MAUDE

One of the objectives in the design and materials engineering has always been to facilitate their use directly or improve their properties to continue to push the boundaries of human activity. Nowadays, materials with higher performance are required, which, inevitably is accompanied by pressure on the environment. For example, optimization of the composition of alloying elements for a particular microstructure is a classical mean of improving material properties such as strength, ductility toughness, corrosion resistance. However, to facilitate recycling, simple combinations of safe and widely available metallic chemical elements must be promoted. Therefore, it is necessary to adopt innovative approaches to the design of materials with less use of alloying elements. Given the above-mentioned context and within the framework of the MAUDE proposal, an innovative development methodology is implemented. It uses dynamic plastic deformation and associated thermal effects to refine the grains in order to improve the mechanical properties. Materials to be studied are nickel and aluminum alloy (Al-Li-Cu, 2000 series such as AA2050). In the latter case, the benefits related to the grain refinement will be combined with those due to the presence of nano precipitates. The innovative character of the project is linked, among other things, to the fact that all these changes and transformations will be achieved in a one step processing stage, revealing a substantial economical processing route. The selected materials meet the dual aspect of the call for proposal because of potential applications in the fields of armaments and transportations. In addition, the selected means deal with industrial dimensions with the elaboration of disks 19 and 100 mm in diameter. To optimize the mechanical properties, the resulting microstructure will be investigated in detail, in a wide range of temperature conditions and mechanical loading, comprising uniaxial tensile and compression tests, as well as simple and cyclic shear loadings. The development in one step process of more or less complex form having the proper microstructure will be proposed at the end of the project.