1

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

1

Structure and Properties

of

MaterialsLecture_1

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

2

Classification of Materials

There are different

ways of classifying

materials

2

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

3

Classification

of

Materials

Ordinary Functional

Based

on

Structure

Common engineering materials that come

within the scope of Material Science may

be classified broadly into the following

three types:-

I. Metals (Ferrous and Non-Ferrous)

II. Ceramics

III. Polymers (Plastics)Semiconductors; and Composites

9/13/2010 ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

4

Ordinary Classification

3

Metals and Alloys

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

5

An alloy is a homogeneous mixture of two or

more elements, at least one of which is a metal,

and where the resulting material has metallic

properties. The resulting substance usually has

different properties from those of its

components.

Alloying one metal with others usually improves

on the properties of other elements

Alloys contain atoms of different sizes, which

distorts the regular arrangements of atoms. This

makes it more difficult for the layers to slide

over each other, so alloys are harder than the

pure metal.

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

6

CeramicsThey are primarily oxides, but can also be

carbides, nitrides, borides, and silicates

Advanced Ceramics

Sensors, actuators,

capacitors, electrical

insulation, barrier coating,

bricks, tableware,

Refractories, abrasives.

are defined as non-metallic inorganic crystalline

Materials

Naturally Occurring

Sand

Rocks

Stones

4

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

7

Polymers

A group of materials

normally obtained

by joining organic

(Hydrocarbons)

molecules into giant

molecular chain or

network.

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

8

Semiconductors

A group of materials having

electrical conductivity between

metals and typical ceramics

5

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

9

Composites

Composite materials are engineered materials

made from two or more constituent materials

with significantly different physical or

chemical properties and which remain

separate and distinct on a macroscopic level

within the finished structure. For example the

most primitive composite materials comprised

straw and mud in the form of bricks for

building construction.

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

10

Functional

classification

of materials,

notice that

metals,

plastics, and

ceramics

occur in

different

categories

Functional

Classification

6

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

11

Classification Based on

Structure

Structure

Crystalline

Amorphous

Atoms are arranged in a periodic fashion

Atoms don’t have in a long-rang order

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

12

The range of crystalline order distinguishes

single crystals, polycrystals and amorphous

solids. The figure shows how the periodicity of

the atomic structure of each type of material

compares.

7

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

13

Crystalline Materials

Metals and alloys;

Most ceramics;

Semiconductors

Amorphous Materials

Glasses;

Most polymers

In your text book

You are request to study the following:

Chapter 1 From page 1 to 13

Study well the title “Materials of

Importance” page 11

9/13/2010ENGR 230

Structures and Properties of Materials

Nahid Abdel Salam

14