This document provides notes on material science concepts. It discusses key points about assignments, quizzes, reports and presentations. It also covers classifications of materials, basic concepts like deformation, stress, strain and mechanical properties including elasticity, ductility, brittleness, hardness and toughness. Graphs of stress-strain curves are presented and terms like elastic limit, yield point and ultimate tensile strength are defined. Students are instructed to submit assignments on time and follow the instructor's directions.

1. Material Science
Eng. Kareem. H. Mokhtar

2. Important notes
 Make sure to submit your work BEFORE the Due date
 50% minus if you submit after it.

3. Assignments
You will get your feed back
After submitting your
assignment and you should:
1- submit before the due date
2- solve all the questions
3- submit your assignment as
neat as possible

4. Quizzes
1- Quizzes will start at a certain time
2- You are not allowed to flip your
quiz until you hear that the quiz will
start now.
3- When you hear put your pens
down, stop answering immediately.
4- Follow the instructor’s directions
Never Cheat !!

5. Report and a presentation
 Form groups of ”2”
 Be on time
 Stick to the time limit

7. Classification
Material can be divided into
1- Crystalline material
These materials contains one or more crystal, In each crystall atoms
show a periodic arrangement.
2- Non- crytalline material (amorphous material)
These materials does not contain a periodic arrangement of ions or
atoms

8. Basic Concepts
 Deformation
 Elastic Deformation
 Plastic Deformation
 Stress
 Strain

9. Deformation
 It is the changes in an object's shape due to the application of a force or several
forces

10. Types of Deformation
 Deformation can be classified into two groups
 1- Elastic deformation
 It is a reversible deformation, which means the body will return to it’s original
shape when the stress is removed
 2- Plastic Deformation
 It is an irreversible deformation (permanent)

11. Stress
 It is the force applied per area of the body
 Different forms of stresses will be discussed later
= F
A
stress

12. Strain

13. Mechanical Properties
 A- Elasticity
 B-Ductility
 C- strength
 D- Hardness
 E- Brittleness
 F-Toughness

14. Elasticity
 Elastic material: material that springs back to its original
shape after the removal of the stress

15. Ductility
 It is the ability of the material to bend or stretch without breaking

16. Brittleness
 The material is said to be brittle if it fails without any plastic deformation
 A- ductile material
 B- moderately ductile
material
 C- Brittle material

17. Hardness
 It is the resistance of the material to scratch or penetration

18. Stress- Strain curve
TS
stress
strain

19. Stress-strain curve
stress
strain
P
P : Proportional limit
E
E : Elasticity limit
Y : Yield point
U
U: Ultimate tensile strength
B: Break point
B
Elastic Plastic
Y

20. Stress-strain curve
 Elasticity limit :
 is the maximum stress within a material can withstand before permanent deformation.
 This point is the limit of the elastic region
 Yield point:
 marks the beginning of plasticity.
 Ultimate tensile strength:
 The maximum stress that a material can withstand while being stretched or pulled before
breaking

21. Toughness
 It is the energy absorbed by the material before fracture
 It is the total area under the curve for the stress-strain up to fracture