Comparing Modulus & Strength of Metals & Plastics

[yong1986]

We done an experiment of tensile test where we used the testometric machine that pulls different kind of material (aluminium, PVC, steel, brass) and generated graph stress/strain and etc, now we come to these questions:

1. Explain why the plastics/ polymer has a lower modulus and strength than the metal.
2. Explain what is happening at the atomic (or molecular) level in the elastic region and the plastic region of each material.


Can anyone provides complete answers?

Thanks!

 

[Topher925]

The answer to your questions has to do with the types of bonding in the materials along with the crystalline structures. I don't have the time to write an entire post about it but do some research on the following topics.

covalent bonds
ionic bonds
metallic bonds
crystalline structures
shear angle
molecular geometry

 

[stewartcs]

We done an experiment of tensile test where we used the testometric machine that pulls different kind of material (aluminium, PVC, steel, brass) and generated graph stress/strain and etc, now we come to these questions:

1. Explain why the plastics/ polymer has a lower modulus and strength than the metal.
2. Explain what is happening at the atomic (or molecular) level in the elastic region and the plastic region of each material.


Can anyone provides complete answers?

Thanks!

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