why do glass and ceramics break when you drop them, while plastics and metals don’t?
In: Chemistry
There is a graph out there that shows the relationship between elastic and plastic deformation as well as failure points. A deformation is changing the shape of something. Usually by force. And elastic deformation is bending an object with force and after the force has been removed it will go back to how it was before you bent it. Plastic deformation will not to return to its original state. And a failure point is where something completely breaks down. Think of a paper clip. If you bend it, it will return back to its original position up until a certain point. If you bend it to far it will stay bent. Plastics will elastic and plastic deform and fail just as glass does the graph is just different. Glass will fail rather quickly but plastics will take more force reach a failure point.
Ceramics have a rigid crystal structure. They cannot take much/any strain before breaking apart, there is no ‘give’ within the material itself (ability for layers to slide over each other without breaking apart entirely). Breaking Strain is a physical property of a material – the extension (before breaking) divided by the length under test. Ceramics also invariably have surface imperfections which are the source of crack propagation, if for example you knock the material it might shatter (at the speed of sound).
Plastics are made up from tangled chains of C based molecules, which can slip and slide over each other while maintaining structural strength, within limits of course.
Metals too are ductile (opposite of brittle) – gold can be drawn to atomic thicknesses, according to Wikipedia, which is a great source of information for questions like this.
Glass and ceramics are brittle
They dont deform instead they respond to pressure or force by breaking
While plastics and metals can bend and arent broken so easily
As to why that happens is something to do with their structure. Maybe someone else can help you out on that i dont know much about that
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