Kingdom of Saudi Arabia, Ministry of Higher Education, ...

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Kingdom of Saudi Arabia,

Ministry of Higher Education,

Jazan University,

Preparatory Year Deanship.

Practical Production Tech. & Workshop

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Practical Production Tech. & Workshop

Assoc. Prof. OSAMA A. HAMED

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Tut./Lab

Lec. Topics

6 4 Engineering Materials3 2 Safety3 2 Measuring Instruments3 2 Tools used in Fitting Shop3 2 Casting3 2 Joining Methods3 2 Turning3 2 Shaping3 2 Milling3 2 Drilling6 4 Metal Forming3 2 Basics of Cars maintenance

Course syllabus:

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CHAPTER ONE

ENGINEERING MATERIALS

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INTRODUCTION

Engineering materials are used to manufacture

the products, dictates which manufacturing

process or processes are to be used to provide it

the desired shape.

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2. PROPERTIES OF MATERIALS

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

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2.1. Mechanical Properties

Mechanical properties describe how a material

responds to an applied force, include strength and

ductility.

Mechanical properties describe how a material

behaves when it is exposed to a sudden, impact,

fatigue, creep or wear.

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2.1.1. Strength

Strength is a measure of how the material resists

being misshapen or deformed, when acted under

force.• Tensile strength الشد إجهادThe ability of the material to withstand pulling forces or tension forces.

•Compressive strength الضغط إجهادIt is the ability of the material to withstand squeezing forces or

compression forces.

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Fig. 1.1 Schematic universal tensile testing machine Fig. 1.2 Stress strain curve for ductile material

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Tensile testing machine

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2.1.2. Torsional properties اإللتواء إجهاد It is the ability of a material to withstand twisting

forces.2.1.3. Hardness الصالدة It is the ability of a material to withstand being

scratched.2.1.4. Toughness المتانة A measure of how much energy is required to

break a material. 2.1.5. Stiffness الجساءة It is the ability to resist bending deformation.2.1.6. Ductility المطيلية It is the ability to be elongated.2.1.7. Brittleness القصافة It is the ability to be resist fracture or

deformation.

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1.CLASSIFICATION OF ENGINEERING

MATERIALS

A large numbers of engineering materials exists in the

universe such as metals and non metals )leather,

rubber, asbestos, plastic, ceramics, organic polymers,

composites and semiconductor). Some commonly

used engineering materials are broadly classified as

shown in 1.3.

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Fig. 1.3 Classification of engineering materials

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)a) Ferrous metals are those which have the iron as their main constituent, such as pig iron, cast iron, wrought iron and steels.)b) Non-ferrous metals are those which have a metal other than iron as their main constituent, such as copper, aluminum, brass, bronze, tin, silver zinc, invar etc.

2.2.1. SteelsSteel is an alloy of iron and carbon with carbon content

maximum up to 1.7%. The carbon occurs in the form of iron

carbide, because of its ability to increase the hardness and

strength of the steel.

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