2. Purpose Of Making Alloys 451k12

Purpose of Making Alloys 1. Metals are used in various fields like in construction of structures, making of various machines used in small scale and large scale industry etc. 2. But as discussed earlier metals are extracted in their purest form and this result in the loss of some of the vital properties of metal. Which is totally undesirable 3. This loss in the properties like tensile strength, hardness etc are improved by mixing metal with some other metal or non metal. 4. Thus making alloys helps us to enhance the desired properties of pure metal 5. Generally the following properties of metals are improved by employing the alloying process. 1) 2) 3) 4)

Colours Tensile Strength Corrosion Resistance Hardness Improvement in characteristics

Sr. No . 1

Characteristics

Main Metal

Alloying Elements

Hardness

Pure Lead

Arsenic (0.5%) Copper

Hardness of lead improves and it is used to make bullets

Pure Gold

Copper

Ornaments of gold are prepared as hardness of gold improves

Pure Iron

Carbon (1.5%)

Pure Copper

Tin, Zinc

2

Tensile Strength

Pure Iron

Carbon (1%)

3

Corrosion Resistance

Pure Iron

Chromium, Nickel

Modification in Properties of Main metal

To make steels with greater hardness Alloy is harder than pure copper Ten times increase in tensile strength of iron The alloy does not get corroded, not only by moisture but even in acids

4

Cast ability

Pure Lead

Tin, Antimony

Cast ability of this alloy improves and hence it is used in making ‘printing type’

5

Colours

Silver (White)

Gold (Yellow)

The alloy is purple coloured

Silver (White)

Tin (White)

Copper (Red)

Zinc (Silvery white)

The alloy is yellow coloured

Aluminium (Silvery white)

Zinc (Silvery white)

The alloy is golden yellow in colour

The alloy is pink coloured