Page 215 - Chemistry ICSE Class X

Metallurgy 201

Table 7.7 Composition, properties and uses of some alloys
Alloy Composition Properties Uses
ALLOYS OF COPPER AND ZINC
Ŗ Brass Cu 60–80% Malleable and ductile, Stronger than Brass is used for decoration purposes,
Zn 20–40% both copper and zinc. HQT OCMKPI OCP[ UEKGPVKſE KPUVTWOGPVU
telescopes, microscopes, barometers,
etc.
Ŗ Bronze Cu 80% Hard, can be polished, corrosion- For making statues, cooking utensils
Zn 10% resistant, Easy to cast. and coins.
Sn 10%
Ŗ German silver Cu 30–60% Malleable and ductile, Silvery, White, It is silvery white as silver, malleable
Zn 25–35% High resistivity. and ductile. It is used as imitation silver
Ni 15–35% in making ornaments and utensils and
also for decoration.
Ŗ Gun metal Cu 88% Hard, Brittle, Easy to cut. It is used for making gears and bearings,
Sn 10% and gun barrels.
Zn 1%
Pb 1%
Ŗ Bell metal Cu 80% Sonorous, Hard and Brittle. It is used for casting bells.
Sn 20%

ALLOYS OF IRON
Ŗ Stainless steel Fe 74% Stainless steel is hard, tenacious and For making cutlery, utensils, ornamental
Cr 18% corrosion-resistant. pieces and some other instrument and
Ni 8% apparatus.
Ŗ Nickel steel Fe 96–98% Nickel steel is hard, elastic and For making electric wire cables,
Ni 2–4% corrosion-resistant. automobile and aeroplane parts,
watches, armour plates, propeller shafts,
etc.
Ŗ Invar Fe 63% 8GT[ NQY EQGHſEKGPV QH GZRCPUKQP 5EKGPVKſE KPUVTWOGPVU OGVTG UECNG
Ni 36%
C 1%

Ŗ Tungsten steel Fe 84% Very hard Cutting tools
W 5%
C 1%
ALLOYS OF ALUMINIUM
Ŗ Duralium or Al 95% In strength, it is as good as steel but it is For aeroplanes, spacecrafts, sea ships
Duralumin Cu 4% very light. It is hard, corrosion-resistant and pressure cookers.
Mg 0.5% and highly ductile.
Mn 0.5%

Ŗ Magnalium Al 90–95% It is hard and tough. For making light instruments, parts of
Mg 5–10% machines and balance beams.

ALLOYS OF LEAD
Ŗ Solder Pb 50% It has a low melting point. Used for soldering purposes.
Sn 50%

Ŗ Type metal Pb 75-80% Low melting, Easy to cast. For making printing type.
Sb 15-20%
Sn 5%