Aluminum Scandium alloys are designed to improve strength, thermal stability and corrosion resistance. They are primarily used in aerospace and industrial applications. For example, they are used in aircraft, missiles and aircraft components.
In addition, aluminium-scandium alloys are used in sports equipment, such as lacrosse sticks, baseball bats and bicycle frames. The alloy is also used in fuel cells, micro-electro-mechanical systems (MEMS) and lasers. These applications have increased demand, as do new applications such as light-weight high-strength aluminum alloys.
Research into scandium-containing aluminum has shown improved physical properties at higher temperatures. However, this new alloy has limitations. It is expensive and has been found to be relatively difficult to manufacture. Therefore, an improved process is needed. This is why Rio Tinto and metal additive manufacturing specialist Amaero have teamed up.
Rio Tinto will supply the first commercial batch of the high-performance alloy to Amaero. They will also work together to develop a supply chain for the alloy.
During production, a molten salt mixture of alumina and aluminum oxide is heated to a temperature of about 600°C. Throughout the production cycle, the concentration of scandium oxide is maintained at between 2 and 8 wt. %.
When the aluminum-scandium alloy is cooled, it possesses the properties of a superplastic aluminum. In cold rolling, the alloy demonstrates increased tensile strengths. Another advantage of the alloy is its higher strength when exposed to high temperatures.
The physical properties of the aluminum-scandium alloy are enhanced by selective aging treatments. The temperature and duration of the aging treatment are chosen to provide the desired effect.