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Wrought aluminum-silicon alloys (4xxx)

Dr. Dmitri Kopeliovich

According to the Wrought aluminum alloys designation system, alloys of this series are designated 4xxx.

This group includes silicon (Si) as the major alloying element.

Copper (Cu), magnesium (Mg), nickel (Ni) and beryllium (Be) may be added to the alloys of 4xxx series as minor alloying elements.

Most of aluminum-silicon wrought alloys are non-heat-treatable (except alloy 4032 containing 1% of magnesium and alloy 4145 containing 4% of copper).

Silicon is added to these alloys in amount up to 13.5% (alloy 4032) in order to decrease their liquidus temperature and to increase their fluidity, since the alloys are used mostly as welding wires or brazing rods (alloy 4343).

Some of the alloys are used in architectural applications due to their specific dark grey color which they obtain when anodized.

Chemical compositions of some wrought aluminum-silicon alloys (4xxx)

Designation Si,% Cu,% Mg,% Ni,% Be,%
4032 11.0-13.5 0.5-1.3 0.8-1.3 0.5-1.3 -
4043 4.5-6.0 0.30 max 0.05 max - 0.0008
4045 9.0-11.0 0.30 max 0.05 max - -
4047 11-13 0.30 max 0.10 max - 0.0008
4145 9.3-10.7 3.3-4.7 0.15 max - 0.0008
4343 6.8-8.2 0.25 max - - -
4643 3.6-4.6 0.10 max 0.1-0.3 - 0.0008

(concentration of aluminum - balance)

Properties of some wrought aluminum-silicon alloys (4xxx)

(Materials Data)

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