Wrought Al Alloys
This aluminium alloys are acquired by addition of Mn and Mg. The Al-Mn and Al-Mg alloys cannot be heat treated. Al-Mn alloy combines high ductility along with excellent corrosion resistance. Beverage cans, cooking utensils and roofing sheets are made in Al-Mn alloy.
Al alloy that responds to heat treatment via age hardening are Al-Cu, Al-Cu-Mg and Al-Mg- Silicon. Several Al alloys, their composition and applications are explained in Table. Duralumin is one that alloy such contain 4 percent Copper and small amounts of Mg, Mn and Silicon. Subsequent to heat treatment this alloy develops UTS of 450-550 MPa and finds employ in aircraft structures.
Apart from cast and wrought alloys the superior tonnage as about 85percent of Al is utilized in commercially pure form whether impurities are less than 1%. Al extrusions, rods, tube, wire, chemical process equipment, electrical conductors, foils and a lot of architectural fittings are made in commercially pure Al. The aluminium properties are explained in Table.
Table: Several Aluminium Alloys - Properties and Applications
|
Alloy
Designation
|
Composition (% )
|
UTS/Elongation (% ) N/mm2
|
Characteristics and Applications
|
|
EC - O
|
99.5 Al (mini)
|
75/50
|
Ductile, high electrical conductivity
|
|
3003 - O
3003 - H16
|
98.8 Al, 1.2 Mn
98.8 Al, 1.2 Mn
|
130/140
190/140
|
Good formability and corrosion resistance weldable, storage and utensils
|
|
2024 - T4
|
93 Al, 4.5 Cu, 1.5 Mg,
0.5 Si, 0.5 Mn
|
500/19
|
High strength, aircraft parts, bridges, rivers
|
|
5056 - H18
5056 - O
|
94.6 Al, 5.2 Mg, 0.3 Mn
94.6 Al, 5.2 Mg, 0.3 Mn
|
450/10
300/35
|
Good corrosion resistance to sea water good finish when buffed or anodized, marine parts, cooking utensils, bus bodies
|
|
6061 - T6
6061 - O
|
98 Al, 1 Mg, 0.6 Si, 0.4 Cu
98 Al, 1 Mg, 0.6 Si, 0.4 Cu
|
320/17
|
Good corrosion resistance and formability, general structure, anodized articles, marine and transport parts
|
|
7075 - T6
7075 - O
|
90 Al, 5.5 Zn, 2.5 Mg,
1.7 Cu, 0.3 Cr
90 Al, 5.5 Zn, 2.5 Mg,
1.7 Cu, 0.3 Cr
|
600/11
240/16
|
High strength and corrosion resistance, aircraft parts, bridges
|
Table: Typical Properties of Aluminium
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Sl. No.
|
Property
|
Value
|
|
1
|
Purity %
|
99.5 Al, 0.25 Si, 0.25 Fe
|
|
2
|
Melting point oC
|
660
|
|
3
|
Sp. Gravity
|
2.70
|
|
4
|
Tensile strength, N/mm2
O - Temper
H - 18 Temper
|
72
135
|
|
5
|
Elongation % O - Temper
H - 18 Temper
|
60
17
|
|
6
|
Hardness BHN O - Temper
H - 18 Temper
|
19
35
|
|
7
|
Electrical conductivity* % IACS O - Temper
H - 18 Temper
|
62
61
|
|
8
|
Thermal conductivity
J/m2/oC/s at 25oC
|
234
|
|
9
|
Corrosion resistance
|
Very good in rural marine and industrial, atmosphere
|