Question

1-Sketch and explain difference among typical metal, ceramic and polymer behavior through stress-strain diagram.Sketch and explain difference among typical metal, ceramic and polymer behavior through stress-strain diagram.

Text Book- The Science and Engineering of Materials, Askeland et al. (seven edition)

Home Work- # 6 for Chapter 6

please sovle the question and type the answer in the computer

thanks,

Answer 1

The stress strain curve for each material is given above.For metals we see that they go a large and considerable amount of plastic deformation after the yielding and they have larger area under stress strain curve hence higher strain energy per unit volume hence higher shock bearing capability.

In case of ceramics we never see any plastic deformation.They are hard and break immediately after some point so yield point is not defined for them they have only ultimate stress defined.They have very low strain energy per unit volume.

For polymers like polyethelene the breakage happen in steps the weaker bonds break first(like C-H bonds in Polyethelene) and then stronger bonds break (like C-C in polyethelene),hence we see peaks and valleys in stress strain curve.Polymers don't break entirely and instantly but they show very large deformation before complete failure.