A Comprehensive Guide to Classifying the Different Properties of Engineering Materials

 

What are Engineering Materials and How do We Classify Their Properties?

Engineering materials are substances that are used to construct machines, tools and other objects. They can be either natural or synthetic, and they have different physical and chemical properties which make them suitable for various engineering applications. In order to classify their properties, engineers use a variety of methods such as mechanical testing, thermodynamic analysis, electrical conductivity tests and more. Each method provides a unique insight into the characteristics of the material which helps engineers choose the best material for their particular application.

 

The 7 Main Categories of Material Properties and What They Mean

The important properties of an engineering material determine the utility of the material which influences quantitatively or qualitatively the response of a given material to imposed stimuli and constraints. The various engineering material properties are given as under.

1. Physical properties

2. Chemical properties

3. Thermal properties

4. Electrical properties

5. Magnetic properties

6. Optical properties, and

7. Mechanical properties

 

These properties of the material are discussed as under

 

1. Physical Properties

The important physical properties of the metals are density, color, size and shape (dimensions), specific gravity, porosity, luster etc. Some of them are defined as under.

(i) Density

Mass per unit volume is called as density. In metric system its unit is kg/mm3. Because of very low density, aluminium and magnesium are preferred in aeronautic and transportation applications.

(ii) Color

It deals the quality of light reflected from the surface of metal.

(iii) Size and shape

Dimensions of any metal reflect the size and shape of the material. Length, width, height, depth, curvature diameter etc. determines the size. Shape specifies the rectangular, square, circular or any other section.

(iv) Specific Gravity

Specific gravity of any metal is the ratio of the mass of a given volume of the metal to the mass of the same volume of water at a specified temperature.

(v)  Porosity

A material is called as porous or permeable if it has pores within it.

 

2. Chemical Properties

The study of chemical properties of materials is necessary because most of the engineering materials, when they come in contact with other substances with which they can react, suffer from chemical deterioration of the surface of the metal. Some of the chemical properties of the metals are corrosion resistance, chemical composition and acidity or alkalinity. Corrosion is the gradual deterioration of material by chemical reaction with its environment.

 

3. Thermal Properties

The study of thermal properties is essential in order to know the response of metal to thermal changes i.e. lowering or raising of temperature. Different thermal properties are thermal conductivity, thermal expansion, specific heat, melting point, thermal diffusivity. Some important properties are defined as under

 

4. Electrical Properties

The various electrical properties of materials are conductivity, temperature coefficient of resistance, dielectric strength, resistivity, and thermoelectricity. These properties are defined as under.

 

(i) Conductivity

Conductivity is defined as the ability of the material to pass electric current through it easily i.e. the material which is conductive will provide an easy path for the flow of electricity through it.

(ii) Temperature Coefficient of Resistance

It is generally termed as to specify the variation of resistivity with temperature.

(iii) Dielectric Strength

It means insulating capacity of material at high voltage. A material having high dielectric strength can withstand for longer time for high voltage across it before it conducts the current through it.

(iv) Resistivity

It is the property of a material by which it resists the flow of electricity through it.

(v) Thermoelectricity

If two dissimilar metals are joined and then this junction is heated, a small voltage (in the milli-volt range) is produced, and this is known as thermoelectric effect. It is the base of the thermocouple. Thermo -couples are prepared using the properties of metals

 

5. Magnetic Properties

Magnetic properties of materials arise from the spin of the electrons and the orbital motion of electrons around the atomic nuclei. In certain atoms, the opposite spins neutralize one another, but when there is an excess of electrons spinning in one direction, magnetic field is produced. Many materials except ferromagnetic material which can form permanent magnet, exhibit magnetic affects only when subjected to an external electro-magnetic field. Magnetic properties of materials specify many aspects of the structure and behavior of the matter. Various magnetic properties of the materials are magnetic hysteresis, coercive force and absolute permeability which are defined as under.

 

6. Optical Properties

The main optical properties of engineering materials are refractive index, absorptivity, absorption co-efficient, reflectivity and transmissivity. Refractive index is an important optical property of metal which is defined as under.

 

7. Mechanical Properties

Under the action of various kinds of forces, the behavior of the material is studied that measures the strength and lasting characteristic of a material in service. The mechanical properties of materials are of great industrial importance in the design of tools, machines and Porperties and Testing of Metals 119 structures. Theses properties are structure sensitive in the sense that they depend upon the crystal structure and its bonding forces, and especially upon the nature and behavior of the imperfections which- exist within the crystal itself or at the grain boundaries. The mechanical properties of the metals are those which are associated with the ability of the material to resist mechanical forces and load.

The main mechanical properties of the metal are

• strength, 
• stiffness,
• elasticity, 
• plasticity, 
• ductility, 
• malleability, 
• toughness, 
• brittleness,
• hardness,
• formability, 
• castability and weldability. 

These properties can be well understood with help of tensile test and stress strain diagram.

 

How Do We Identify the Different Types of Mechanical Properties?

Mechanical properties are the physical characteristics of a material that determine how it behaves under different types of loads and environmental conditions. Understanding these properties is essential for engineering and manufacturing processes, as they can help us identify the best material for a particular application or product. In this article, we will look at the different types of mechanical properties and how to identify them. We will also discuss some examples of common mechanical tests used to measure these properties in materials.

 

 

Understanding Thermal & Electrical Properties in Relation to Engineering Materials

Engineering materials are used in a variety of industries, from aerospace to automotive engineering. Understanding the thermal and electrical properties of these materials is essential for engineers to make sure that their designs will perform as expected. This article will provide an overview of thermal and electrical properties, as well as how they relate to different engineering materials. It will also discuss the use cases for these properties in engineering applications, and how they can be measured in order to ensure optimal performance.

 

 

Identifying Chemical & Physical Properties for Optimized Performance

Identifying the chemical and physical properties of a material is an important step in optimizing its performance. By understanding how these properties interact with each other, we can better control the performance of a material and ensure that it meets our desired specifications. Moreover, by understanding how these properties affect the behavior of a material, we can design materials that are more efficient and cost-effective. This knowledge can be used to improve existing products or create entirely new ones.

 

Conclusion

Engineering materials are an important component of any engineering project. They can be used in a variety of ways, from providing structural support to creating aesthetic appeal. Each type of material has its own unique set of properties that make it suitable for certain applications. In this article, we will discuss the different properties of engineering materials and how they can be used in various applications. We will also look at some examples to illustrate how these properties can be utilized to create successful projects.