I knew that crucibles made of alumina ceramics can with withstand very high temperatures but I was surprised to note that the same alumina ceramics is also applied in bullet proof vests. I chanced upon this knowledge only yesterday.
While I was clearing the garage junk, I found a pulley made of nylocast. My must have gotten it when he was working in a chemical industry. A structural engineer who was helping me in the cleaning work picked it up and told me it resembled alumina ceramics.
A pulley made of ceramics? I thought ceramics are so brittle. He them explained the magical physical properties of aluminum oxide which when mixed with ceramics gave out a sturdy material that can even resist radiation.
He went on to explain the various applications of alumina ceramics and among them was the bullet proof vest. I still could not digest that fact.