Question: why do you smash ceramics to hear what they sound like

Andy Norton answered on 10 Jun 2011:

Hey guys!

The idea of smashing ceramics came because people don’t really understand this at the moment. For example, people in the military are making plates to go on the outside of tanks – these are made of ceramics, like the type of thing that you eat off (although a bit more fancy!). So that they can make these as strong and as hard as possible (hard enough to stop bullets from both hand-held guns and maybe even from tanks), people needed to investigate how and why ceramics break when they are hit. If we can work out how they break when smashed (either with a bullet, or in a compressing machine like I use), then maybe we can work out how to make them better.

The reason that we are listening to the noise that they make it because it might be able to tell us something about how it is breaking. It could be that there are tiny cracks forming inside before it breaks, or it could be deforming (like producing deformation twins – did you see the picture of this that I put on my profile? If not, [myimage2 right] (I’m not sure if that works – ignore that code if it doesn’t!), or it could be doing something else. So that we don’t have to cut the sample open each time to work out how they broke, we could use the noise that they make to work out what is going on.

So, yeh, it’s basically to try and get better armour for tanks!