Why is graphite used to building heavy duty things??

Question

graphite itself is suppose to be one of the softest minerals known, but it is often the high stenghth component to building heavy duty things such as automobiles and aircraft..why is this so??

please explain as thoroughly as possible!! thanks!!

Answer 1

graphite is not used for building anything that I know of.

You are thinking of carbon fiber, which is a different crystalline structure than graphite, just as diamond is.

Answer 2

Careful:  Graphite is not used for heavy-duty things - it is used for heavy-duty things that need to be lightweight.

Graphite is a polymorph of carbon and has a carbon-carbon bond, similar to a diamond.

The big difference is that the diamond has a crystal structure, where graphite is structured in flat sheets.  Each sheet is very strong, but slides very easily against those above and below it.  With proper epoxy binders, these sheets can be "rolled up" to make very high-strength composites.

When strength-to weight factors are considered, they are superior to most other materials.  Yet, graphite composites are very expensive to make and are not the first choice for heavy-duty manufacturing.  They are usually the material of last resort, used when all of the less expensive light-weight alternatives have been exhausted.