Aluminium alloy research creates hope of benefit for manned space missions

Dr Matheus Tunes in support with Microscopes and Ion Accelerators for Materials Investigations researched a new alloy that will toughen aluminium without increasing its weight materially.

The spacecraft which are blast-off from earth requires being light; however, it still needs the précised amount of fuel to reach the orbit. If it is bulky, the amount of fuel required would be restrictive. Once a spacecraft is outside of the earth’s protective magnetic field, it may then be exposed to potentially destructive amounts of solar radiation, which becomes more important for any long-duration mission such as to Mars.

Now developing spacecraft from aluminium is one solution as aluminium is a light yet strong material. Alloys enhance aluminium become harder via precipitation strengthening, but the radiation encountered in space can dissolve the hardening precipitates with potentially disastrous and fatal consequences for astronauts.

While the research carried out at MIAMI-2 in partnership with Montanuniversitaet Leoben (MUL) in Austria has explored that a particular hardening precipitate of a new aluminium alloy developed by a group of metallurgists led by Professor Stefan Pogatscher (MUL) does not dissolve when bombarded with particle radiation when compared with existing data on irradiation of conventional aluminium alloys.

The outcome is an alloy with a radiation-resistant hardening phase called a T-phase, which has a complex crystal structure of Mg32 (Zn, Al) 49. The research led to a paper that has been published in the journal Advanced Science.

Dr Matheus, said: "The idea of the paper was testing these new alloys using the MIAMI facilities, because we can subject the alloy to energetic particle radiation and, at the same time, monitor the effect of this radiation on the alloy microstructure with a transmission electron microscope.”

"We monitored the crystallographic signal of the T-phase as the radiation increased and observed that compared with other conventional aluminium alloys, the alloy we developed was radiation-tolerant meaning that the hardening phase does not dissolve under high radiation doses.”

"It sheds light on a very exciting new field of research we call 'prototypic space materials for stellar-radiation environments'. A nuclear reactor is also an extreme environment, as is the sun with solar cycles, but dynamic instabilities on the sun such as solar flares and coronal mass ejections are more extreme than anything on Earth. The sun is a very efficient nuclear fusion reactor and high-energy particle accelerator."

Dr Graeme Greaves, a Senior Research Fellow at the MIAMI Facility, added: "When Matt first came to us from Brazil as a postgraduate student he was always looking for new projects and created several new collaborations, and I'm very happy that as he is starting the next part of his career in Austria and expanding into new areas, he is continuing to collaborate with us here at the MIAMI facility, with this aluminium alloys project being just one example."