Today, the body of an ordinary family car consists of 193 different types of
steel. The steel for each part of the car has been carefully selected and optimized.
It is important, for example, that all parts are as light as possible because of
the fuel consumption, whereas other parts of the car have to be super strong in
order to protect passengers in a collision.
Super strong nanostructured metals are now entering the scene, aimed at
making cars even lighter, enabling them to stand collisions in a better way
without fatal consequences for the passengers. Research into this field is being
conducted worldwide. Recently, a PhD student from the Materials Research
Division at the Technical University of Denmark took research a step further by
discovering a new phenomenon. The new discovery could speed up the practical
application of strong nanometals and has been published in the Proceedings of the Royal Society.
The research task of the student, Tianbo Yu, is to determine the stability
in new nanostructured metals, which are indeed very strong, but also tend to
become softer, even at low temperatures. This is due to the fact that
microscopic metal grains of nanostructured metals are not stable—a problem of
which Tianbo Yu’s discovery now provides an explanation.
The fine structure consists of many small metal grains. The boundaries
between these metal grains can move, also at room temperature. At the same time
a coarsening of the structure takes place and the strength of the nanometal is
consequently weakened. Tianbo Yu’s has now shown that the boundaries of the
grains can be locked, when small particles are present and that the solution is
technologically feasible. This has paved the way for car components to be made
of nanometals.
“We are cooperating with a Danish company and also a Danish consulting
engineering company with the purpose of developing light and strong aluminium
materials with a view to their application in light vehicles where especially
deformation at high rate as in a collision is in focus. The new findings will
be included in this work,” says Dorte Juul Jensen, head of division and Dr.
Techn. She is happy that the excellent findings also have practical
applications.
