In materials science, metals are known for their distinctive physical properties, which make them useful in a wide range of applications. Here are the key physical properties of metals:

1. Luster

• Metals have a shiny appearance when polished, known as metallic luster, due to their ability to reflect light.

2. Conductivity

• Electrical Conductivity: Metals are excellent conductors of electricity due to the presence of free-moving electrons in their atomic structure.
• Thermal Conductivity: Metals also conduct heat well, which makes them useful in applications requiring efficient heat transfer.

3. Malleability and Ductility

• Malleability: Metals can be hammered or rolled into thin sheets without breaking. This property is crucial for processes like forging, rolling, and sheet metal forming.
• Ductility: Metals can be drawn into wires without breaking. This property is important for wire and cable manufacturing.

4. Strength

• Metals generally possess high tensile strength, meaning they can withstand significant pulling forces without breaking.
• Compressive Strength: Metals can also withstand significant compressive forces.

5. Density

• Most metals have high densities, meaning they are relatively heavy for their size. This is due to the closely packed atoms in their crystalline structure.

6. Melting and Boiling Points

• Metals typically have high melting and boiling points, allowing them to remain solid at high temperatures. This property is crucial for high-temperature applications.

7. Hardness

• Metals vary in hardness, which is a measure of their resistance to deformation and scratching. Hard metals are often used in cutting tools and machinery.

8. Elasticity and Plasticity

• Elasticity: Metals can return to their original shape after being deformed by an external force, up to a certain limit.
• Plasticity: Beyond the elastic limit, metals can undergo permanent deformation without breaking. This property is essential for metal forming processes.

9. Toughness

• Toughness is the ability of a metal to absorb energy and plastically deform without fracturing. It combines strength and ductility and is critical for applications involving impact and shock loading.

10. Magnetic Properties

• Some metals, such as iron, cobalt, and nickel, exhibit magnetic properties, making them useful in electrical and electronic applications.

11. Corrosion Resistance

• While many metals are prone to corrosion (especially iron and steel), some metals like aluminum, stainless steel, and titanium have good corrosion resistance. This property is enhanced through treatments like coating and alloying.

12. Optical Properties

• Metals have distinct optical properties such as reflectivity and opacity. They reflect visible light and are opaque to both visible and ultraviolet light.

13. Thermal Expansion

• Metals expand when heated and contract when cooled. The coefficient of thermal expansion measures the degree of expansion or contraction with temperature changes.

14. Crystal Structure

• Metals have specific crystal structures such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP). These structures influence their mechanical properties and behavior under different conditions.

15. Workability

• Metals can be worked into various shapes and forms through processes like casting, forging, rolling, and machining, thanks to their combination of ductility, malleability, and toughness.

Understanding these physical properties is essential for selecting the right metal for a specific application and for predicting how metals will behave under different conditions and in various manufacturing processes.

The following table gives some selected properties for selected materials.

 

Material	Specific Weight N/cc	Melting Point  o C	Modulus of Elasticity E , N/mm2	Modulus of                Rigidity G ,N/mm2	Thermal Conductivity K , Cal/s cm 0C	Coefficient Of linear Expansion ∞ µm/m0C	Poisson’s Ratio
Aluminium   Brylium   Brass   Bronze   Cast iron   Copper   Lead   Monel metal   Stell  C 15   Stell  C 35   Stell  C 60   Titanium   Tungsten   Zirconium	0.027   0.0182   0.0845   0.0873   0.072   0.0896   0.1134   0.0858   0.0785   0.0784   0.0783   0.0454   0.1930   0.0650	660   1280   900-950   910-1040   1150-1300   1083   327   1315-1350   1510   1490   1470   1800   3410   ב1850	0.675 x 105   2.928 x 105   0.970 x 105   1.110 x105   1.000 x105   1.230 x105   0.160 x105   1.590 x105   2.080 x105   2.060 x105   2.040 x105   1.050 x 105   4.153 x 105   0.679 x105	0.260 x 105       0.350 x105       0.350 x105   0.390 x 105   0.076 x 105   0.670 x105   0.790 x105   To   0.890 x105       1.770 x105	0.530   0.380   0.310   0.160   0.130   0.940   0.083   0.060   0.120   0.120   0.110   0.041   0.480   0.040	23.8   12.3   16.7   17.3   9.0   16.2   28.3   14.0   11.1   11.1   11.1   11.8   4.5   10.0	0.34       0.30-0.40       .0.23   0.26   0.45   0.32       0.30           0.17