Mar 16 2009
Combining different metals could create alloy with properties superior to both metals, but that is not true of all metals. Recently an international research team discovered that previously impossible alloys can be created by subjecting atoms to high pressure.
Carnegie Institution 's Mao Ho-kwang, also academician of Chinese Academy of Sciences (CAS) and Jiang Jian-zhong of the International Center for New-Structured Materials, Zhejiang University, China, led the research. The related paper was published in the Proceedings of the National Academy of Sciences.
Previous studies have shown that at pressure thousand of times larger than atmospheric pressure atoms will undergo properties change and form new alloys. Both cerium and aluminum form many useful alloys with other metals, but a cerium-aluminum alloy appeared to be mission impossible. However, Metallic glass began to show the properties of an alloy when high-pressure experiments on a sample of cerium-aluminum. The net result is that both size and electronic structure are put in range that the cerium and aluminum atoms form an alloy.
A lot of high pressure materials can be made, but once the pressure is reduced they go back to their original form. People cannot make anything useful from those materials. But this alloy is quenchable, meaning that the alloy persists when the pressure is gone, and that creates possibilities, noted Mao. The researchers are currently investigating the properties of the new alloy.
Mao notes that the success in producing this new alloy implies that other potentially useful combinations can be made under high pressure. It opens up possibilities for new materials in the future.