The role of Vacancy-Assisted Nanostructure Formation in Light Alloys for application in aerospace and automobiles
- Chief Supervisor
- Prof TJ Bastow (CSIRO)
- Centre Nodes
- CSIRO, ANSTO
The high strength, stiffness and low density make aluminium-based alloys important materials for applications in aerospace and automobiles. The strength and toughness of these lightweight alloys, is created through an age hardening time-temperature processing sequence. The type of sequence used to process and the solute used to dope the aluminium result in varied nucleation and growth of the final precipitate structure. This can result in vacancies, variation in solute distribution, and solute-vacancy interactions that have a significant role in age hardenable aluminium alloys. Controlling these factors is crucial for development of superior lightweight alloys for transportation applications.
In this project alloying strategies and characterisation techniques, such as solid-state nuclear magnetic resonance and positron spectroscopy, will be used to prepare experimental and structural alloys and to observe solute distribution, vacancy concentration and vacancy solute interactions. These alloys will be characterised in terms of residual solute and defects available for dynamic precipitation in order to explore defect tolerant and self-healing alloy structure strategies. Positron Spectroscopy techniques (PALS) will be used to detect the structural changes, and data will be correlated with the mechanical properties of the material. These strategies will be explored using NMR, positrons, neutron diffraction and radiotracer diffusion methods to probe the space available for atomic transport and the transport processes.
The project is a collaboration between CSIRO and ANSTO and the student will need to be willing to travel and work for short periods at ANSTO, Sydney. The student will be expected to work within a diverse team of chemists, radiochemists, chemical engineers, physicists, mathematicians and biologists. They will need to have an interest in materials science and condensed matter physics and a willingness to handle radioactive materials.
Selected Reading
TJ Bastow, "Cu-63 NMR analysis of microstructure evolution in Al-Cu-Mg alloys", Phil Mag 85 (2005), 1053.
TJ Bastow, S Celotto, "Structure evolution in dilute Al(Cu) alloys observed by Cu-63 NMR", Acta Mat 51 (2003): 4621.
A. Thurer et al., "Temperature and pressure dependence of Ge diffusion in aluminium", Phys Stat Sol A, 149 (1995), 535.
A. Dupasquier, G Kogel, A Somoza, "Studies of light alloys by positron annihilation techniques", Acta Mat, 52 (2004) 4707.
Key words: vacancy, light alloys, transport, nanostructure, radiochemistry, aerospace
