Rubbery metal

Vibrations are the bane of engineers, who often go to great lengths to get rid of them. In the worst scenarios, unwanted vibrations can lead to loss of life, for example when they cause cracks to spread in an aircraft's turbine blades. At the other end of the scale, unwanted vibrations may merely make power tools, baseball bats, or tennis rackets uncomfortable and jarring to use.The conventional way to get rid of vibrations is to use some kind of suspension system that dampens them out – perhaps rubber mountings, or an active system that moves in a way that cancels out the vibrations.But what if the metal itself could dampen vibrations, just like rubber? That's exactly what researchers from Virginia Polytechnic Institute and State University in Blacksburg, US, claim to have come up with.Their exotic material is a composite consisting of ceramic particles embedded in a metal matrix. The metal provides strength and stiffness, while the ceramics have a curious property known as ferroelasticity, meaning vibrations are converted into tiny rotations of crystals within the material. The composite offers the strength of a conventional metal with the vibration-dampening properties of rubber.The aerospace industry is notoriously conservative when it comes to incorporating new materials. And, a lot of work will have to be done characterising this material's properties before aerospace engineers will touch it. So, for a while we're more likely to see new material in those non-life-threatening applications, like baseball bats and tennis rackets.