Topic: Optimizing Friction Stir Welding and Alloy Design to Ensure the Durability of Light Weight Carriages in the Australian Rail Fleet
There is a two-part focus to ultimately make aluminium alloys weldable using the friction stir welding (FSW) process (FSWP). The first part entails redesigning aluminium alloy formulations by addition of grain refinement alloys to prevent recrystallisation annealing resulting from FSWP. The second part is optimisation of the FSWP by assessing tool design and operating parameters to reduce the heating of the material, thereby keeping below the critical temperature required for recrystallisation to take place.
FSW has been applied in the rail industry for construction of lightweight carriages, however application has been limited to internal framework and flooring. These limitations are due to the thermal cycle effect the process has on the heat-affected zone (HAZ), themomechanical affected zone (TMAZ) and weld zone (WZ) of aluminium alloys. Strengthening precipitates (SP) within aluminium alloys typically pin grain boundaries in place while dislocations provide mechanical strength. However, when a thermal cycle is induced by frictional heating, recrystallisation and grain growth occurs, resulting in loss of mechanical strength to each zone to levels well below that of the base metal.
- Research Assistant at RMIT under Professor Ivan Cole part of the Rapid Development and Fabrications team, researching feasibility in utilizing quantum nanoparticles for qualitative and quantitative detection of electrochemical corrosion.
- Supervisor: Prof. Ivan Cole (RMIT)
- Supervisor: Dr. Xiao-Bo Chen (RMIT)
- Collaborator: Prof. Daniel Liang (CSIRO)
- Collaborator: Dr. Kun Yang (CSIRO)
- Moreira, P. M. G. P., Figueiredo, M. A. V. and Castro, P. M. S. T. (2007) ‘Fatigue behaviour of FSW and MIG weldments for two aluminium alloys’, Theoretical and Applied Fracture Mechanics , 48, pp. 169–177.
- Teh, N. J., Goddin, H. and Whitaker, A. (2011) Developments in micro applications of friction stir welding. Available at: https://www.twi-global.com/technical-knowledge/published-papers/developments-in-micro-applications-of-friction-stir-welding/ (Accessed: 5 June 2018).