Properties of Engineering Material

A quality that defines a specific characteristic of material is termed as a property. The properties of a material provide a basis for predicting its behavior under various conditions. They are the tools the engineer uses to solve his material problems. Some of the most important properties of engineering material are:                                                                                                                                                                                    

1 .     Physical Properties         :     Size, Shape, density, porosity, structure.                   

 2.      Mechanical properties  :     Strength, elasticity, plasticity, stiffness, ductility, malleability,                                                 resilience, creep.

3.      Chemical properties   :     Corrosion resistance, acidity, alkalinity, chemical,    Composition.

4.      Thermal properties     :     Specific heat, thermal expansion, conductivity.

5.      Magnetic properties   :      Permeability, cohesive force, hysteresis.

6.      Electrical properties    :      Conductivity, dielectric permittivity, dielectric strength.   

Fundamentally, the properties of a material depend on the nature of that particular material alone. Nearly all those properties listen, however, are also inseparably tied in with conditions of use environment and the state of the material. The actual evaluation of a property depends on all these factors. Mechanical strength, for example, differs for various forms of loading, and is commonly expressed by such terms as tensile strength, or fatigue strength. Most properties of engineering materials must be evaluated entirely by experiment: certain specific conditions are applied and the corresponding properties are measured. Experiments for determining properties of engineering materials are usually called tests. Tests may provide properties for use in design or information on the quality of a material. The procedures are usually are standardized because if identical procedures are always followed the result of a number of tests may be compared with some assurance.

 Much of the standardization is done by the national organization set up in each country to improved the use or materials in engineering constructions and also in industries. Some of these organization are (1) BSI (British Standard Institute), (2) AASHO (American Association of State Highway Official), (3) ASTM (American society of testing materials), (4) ACL (American Concert Institute). Each organization gives standard test methods of all kinds in addition to standard specifications for materials and standard definitions of terms.