1. Mechanical Properties of Metals
Strength
Ductility
Hardness
Stiffness
Toughness
Behavior in service:
Fatigue
Ductile-to-brittle transition

2. Strength: a standard tensile specimen

3. Strength: testing machines for tension and bending

4. Strength: a stress-strain diagram (I field – elastic deformation, II field – plastic deformation, III field – necking)
Hooke’s law:
σ = Е·ε.
E is the modulus of elasticity,
or Young’s modulus.

5. Strength: geometry of the deformed specimen

6. Strength: a stress-strain diagram of ductile and brittle metal

7. Typical Mechanical Properties of Several Metals and Alloys
Strength: Typical values of yield strength, tensile strength, and ductility
Typical Mechanical Properties of Several Metals and Alloys
in an Annealed State
Metal Alloy
Yield Strength,
MPa
Tensile Strength,
Ductility, %EL
[in 50 mm]
Aluminum 35 90 40
Copper 69
200 45
Brass (70%Cu–30%Zn) 75
300 68
Iron
130
262
Nickel
138
480
Steel (1020)
180
380 25
Titanium
450
520
Molybdenum
565
655

8. Hardness
- Rockwell tester
- Brinell tester
- Vickers tester

9. Hardness: microhardness indentation of two grains

10. Toughness: impact pendulum-type testing machine

11. Toughness: impact test and specimens

12. Fatigue: fracture surface

13. Fatigue: reversed stress cycle

14. Ductile-to-brittle transition