Comparing Modulus & Strength of Metals & Plastics

Click For Summary
SUMMARY

This discussion focuses on the comparison of modulus and strength between metals and plastics, specifically through a tensile test conducted using a Testometric machine on materials such as aluminum, PVC, steel, and brass. The key findings indicate that plastics exhibit lower modulus and strength due to their molecular structure and bonding types, including covalent, ionic, and metallic bonds. Additionally, the atomic-level behavior in both elastic and plastic regions significantly differs between these materials, influenced by their crystalline structures and molecular geometry.

PREREQUISITES
  • Understanding of tensile testing and stress-strain graphs
  • Knowledge of covalent, ionic, and metallic bonding
  • Familiarity with crystalline structures in materials science
  • Basic concepts of molecular geometry and shear angle
NEXT STEPS
  • Research the differences in mechanical properties of polymers versus metals
  • Study the effects of bonding types on material strength and elasticity
  • Learn about the atomic structure and behavior of materials under stress
  • Explore advanced tensile testing techniques and equipment
USEFUL FOR

Materials scientists, mechanical engineers, and students studying material properties and testing methodologies will benefit from this discussion.

yong1986
Messages
1
Reaction score
0
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!
 
Physics news on Phys.org
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
 
yong1986 said:
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!

Forum guidelines require you to give your thoughts (i.e. make an attempt).

CS
 

Similar threads

Confusion Calculating Young's Modulus
  • · Replies 5 ·
Replies
5
Views
2K
Force needed for hole punch in Metal
  • · Replies 1 ·
Replies
1
Views
2K
Young's Modulus and the Poisson Ratio of Aluminium
  • · Replies 1 ·
Replies
1
Views
2K
What is the Young's Modulus of Aluminum, Steel, and Brass?
  • · Replies 14 ·
Replies
14
Views
3K
Stress-Strain Graphs of different materials
  • · Replies 9 ·
Replies
9
Views
7K
12 ton frame lowered on plastic --> What Happens?
  • · Replies 10 ·
Replies
10
Views
2K
Extracting mechanical properties from strain-stress plot (real test)
  • · Replies 5 ·
Replies
5
Views
1K
Graduate Measuring Tensile Strength in an alternative way
  • · Replies 2 ·
Replies
2
Views
3K
Understanding Yield Strength & Stress Strain Curve
  • · Replies 2 ·
Replies
2
Views
6K
High School Question about stress - strain graph and definition of hardness
  • · Replies 4 ·
Replies
4
Views
2K