Ecole Nationale d'Ingénieurs de Tarbes (ENIT) in France
The ESR will have to explore the capabilities of these innovative techniques, to analyse and understand the physical phenomena occurring during the process. Firstly, ESR8 will have to provide dedicated standard test cases, in order to establish the experimental framework needed to simulate the FSW process. This framework will form the starting point for the global simulation.
During her/his investigation, ESR8 will have to quantify the mechanical and thermal solicitations from the tests carried out, in order to implement the FEM model developed by the academic partners. This section is based on acquisition of the strain and strain rate fields of the material and the temperature flux measurement. These thermo-mechanical fields will be compared with the global simulation results obtained by ESR5 and ESR6. The last stage, will be to Identify and model the physical phenomena occurring during the FSW process for the 3 selected alloys. The objective here is to establish the thermo-mechanical and metallurgical history undergone by the material during the process. This development includes the use of metallurgical methods, as well as thermal and kinematic analyses. The material observations will be compared with those obtained by ESR1 and ESR2.
All tests will be performed using the industrial means made available by the non-academic partners. During these tests, the strain processes will be analysed with brush forces, temperatures and material flow, and measurements will be made using a dynamometer platform, a thermal camera and a high-speed camera respectively. The ESR8 will then have to implement a method for optimizing process parameters, taking into account the physical quantities monitored. To complete the analysis, the processed parts will be collected and analysed using traditional methods to correlate the dynamic and post mortem methods. The metallurgical observations will be made in the UBx, UPV and LOR laboratories, via traditional microstructural means (optical microscopy, scanning electron microscopy, etc.). One of the biggest challenges will be to propose innovative but realistic methodologies for estimating the different fields during welding, since the process does not allow direct access to measurement.
After providing data on the thermomechanical fields and clearly identifying the different microstructure genesis, ESR8 will have to work closely with ESR1,2,3 to model the dynamic recrystallization phenomena (DRX) that appear in the stirring zone during welding. ESR8 should clearly establish interdependences between microstructure and process parameters for the purpose of producing welds with controlled microstructure.