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Asked by caitlhan to James on 13 Jun 2011.
Question: Does each material get damaged in different ways because of their different properties?
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James Marrow answered on 13 Jun 2011:
Yes – to understand how materials get damaged, you need to understand how they deform and absorb energy.
Metals, for instance, deform by sliding of atomic planes over each other. This absorbs energy and is also the mechanism that toughens metals and makes them ductile. We strengthen metals by making this sliding more difficult, although this also usually makes them more brittle. Ceramics cannot deform by this mechanism as the atomic bonds are too strong, so they crack very easily. We can make ceramics stronger by distributing this damage in a cloud of very small cracks, rather than allowing a single large crack to develop.
To do this needs careful control of the way that materials are processed, and sophisticated microscopes to study the mechanisms of deformation and damage
Comments
caitlhan commented on :
Pretty hi-tec stuff then! Really complicated but sounds interesting too. It sounds similar to rocks too, i find geological studies interesting 🙂
James commented on :
Yes, there are similarities to rocks. The advantage we have in materials is that we can change the material by changing the way we make it. Geologists are kind of stuck with what they’ve got!