Material properties describe how a material behaves under different conditions and determine its suitability for specific applications. These properties are generally classified into several major categories:

What are the properties of materials?

Material properties are the characteristics that describe how a material behaves under different conditions.
They determine how a material responds to forces, heat, electricity, and the environment.
Common properties include mechanical, physical, chemical, and thermal properties.
Understanding these properties helps in selecting the right material for specific applications.

1. Mechanical Properties

These describe how a material responds to applied forces.

Strength: Ability to withstand applied loads without failure (tensile, compressive, shear, bending strength).
Elasticity: Ability to return to original shape after removal of load (e.g., rubber).
Plasticity: Ability to undergo permanent deformation without breaking (important in forming processes).
Ductility: Ability to be drawn into wires; measured by elongation and reduction in area.
Malleability: Ability to be hammered or rolled into thin sheets.
Hardness: Resistance to indentation, scratching, or wear (e.g., Rockwell, Brinell hardness).
Toughness: Ability to absorb energy and resist fracture (impact resistance).
Brittleness: Tendency to fracture without significant deformation.
Stiffness (Rigidity): Resistance to elastic deformation, related to Young’s modulus.
Fatigue Strength: Resistance to failure under cyclic loading.
Creep: Time-dependent deformation under constant stress at high temperature.

2. Physical Properties

These relate to the material’s inherent characteristics not involving chemical changes.

Density: Mass per unit volume.
Porosity: Presence of voids or pores.
Melting Point: Temperature at which material changes from solid to liquid.
Thermal Conductivity: Ability to conduct heat.
Thermal Expansion: Change in size with temperature.
Electrical Conductivity: Ability to conduct electric current.
Magnetic Properties: Response to magnetic fields (ferromagnetic, paramagnetic, diamagnetic).
Optical Properties: Transparency, opacity, reflectivity, refractive index.

3. Chemical Properties

These describe how a material reacts with its environment.

Corrosion Resistance: Ability to resist chemical or electrochemical attack.
Oxidation Resistance: Resistance to reaction with oxygen.
Chemical Stability: Ability to remain unchanged under chemical exposure.
Reactivity: Tendency to undergo chemical reactions.

4. Thermal Properties

These define behavior under temperature variations.

Heat Capacity: Amount of heat required to raise temperature.
Thermal Diffusivity: Rate at which heat spreads through a material.
Thermal Shock Resistance: Ability to withstand sudden temperature changes.

5. Electrical Properties

Important for electrical and electronic applications.

Resistivity: Opposition to electrical current.
Dielectric Strength: Ability to withstand electric field without breakdown.
Permittivity: Ability to store electrical energy.

6. Magnetic Properties

Permeability: Ability to support magnetic field formation.
Retentivity: Ability to retain magnetism.
Coercivity: Resistance to demagnetization.

7. Technological (Manufacturing) Properties

These relate to ease of processing and fabrication.

Castability: Ease of forming sound castings.
Weldability: Ability to be welded without defects.
Machinability: Ease of machining with good surface finish.
Formability: Ability to be shaped by plastic deformation.
Hardenability: Ability to be hardened by heat treatment.

8. Acoustic Properties

Sound Absorption: Ability to absorb sound energy.
Sound Transmission: Ability to transmit sound.

Summary

Material properties determine how a material performs in service and during manufacturing. Engineers select materials by balancing mechanical, physical, chemical, and technological properties to meet design, safety, cost, and performance requirements.