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

Please give feedback.

Stress strain curve tells the behaviour of material subjected to load.

For metals when they are subjected to load they show following stress vs strain relation that tells us that metals are generally ductile in nature they follow elastic nature i.e return to original state upon deformation and beyond the elastic limit, the material will experience plastic deformation and finally after reaching ultimate strength reaches to failure on further extension.

Metals -

Polymers show different stress-strain behaviour and are divided as rigid and flexible platics, fibres and elastomers and this is based on their properties moduli, tensile strength, resistance to deformation, fracture point etc.

Polymers -

Ceramics are brittle and hence fracture before reaching elastic limit. I used example of aluminium oxide and glass to plot the following curve.

Hence we conclude that metals generally show properties of ductile material and have mainly 3 stages of deformation elastic, plastic and fracture. Ceramics are brittle and hence break in one go while polymers may have various behaviours depending on the type.