In the search for efficiency in transport, construction and aeronautics, we will need stronger and lighter materials. For example, electric cars are typically rather heavy thanks to their massive dense lithium ion batteries. Magnesium is light, but its alloys are expensive and difficult to produce in terms of quality control. But a new advancement, achieved by the scientists from the Monash University and Chongqing University will allow creating stronger, lightweight magnesium alloys.
Magnesium alloys are not only expensive, they are not very durable. One of the problems is deformation of lightweight magnesium during thermomechanical processes. Since you don’t want parts of your cars deforming as they get hot, the use of magnesium is still limited. If deformation was not a factor, magnesium alloys could be used instead of steel in many applications. That tendency to deform comes from segregation of the material, which separates solute atoms forming them into single atomic column. In other words, magnesium alloys are not as good as they should be because of segregation, associated with electron beam damage.
Segregations affects the formability, deformation behaviour and tension-compression strength of wrought magnesium products. Now an international team of scientists found a way to use X-Ray mapping to enhance the potential of lightweight magnesium. Atomic-resolution X-ray mapping can be used at 120kV, which is a much lower accelerating voltage of electrons than currently used (300 kV). Professor Jian-Feng Nie, lead author of the study, said: “We further discovered that the new segregation pattern increases the boundary pinning effect by more than 30 times, and switches the migration mechanism of the twin boundary from the commonly accepted mode to a new one”.
In their study scientists used magnesium alloy with neodymium and silver. This kind of alloy is great in structural areas, especially in machinery and various vehicles, because it has superior mechanical properties at both ambient and elevated temperatures. Researchers found that neodymium and silver made the alloy better at withstanding shear stress. This makes for a very strong and yet lightweight alloy and all thanks to X-Ray mapping and structural analysis on the molecular level.
So what can scientists do now with this newly acquired knowledge. Well, they need to design a process, which would allow creating this alloy in an automated way with high-quality results. Economy is in scale and metals have to be produced in large quantities. Hopefully, very soon this will yield a revolution in transportation sector and construction.
Source: Monash University