Alloy AK8 is used: for the production of highly loaded parts of aircraft; parts operating in conditions of cryogenic temperatures; large extruded pipes; casting into metal mold.

Note

ISO 209−1 alloy AK8 is the brand designation АlCu4SiMg and 2014.
Heat-treatable alloy of high strength. For corrosion resistance of the alloy to aluminum-silicon alloys.

Standards

Name	Code	Standards
Bars	В55	GOST 21488-97, GOST Р 51834-2001, OST 1 90395-91
Non-ferrous metals, including rare, and their alloys	В51	GOST 4784-97, OST 1 92014-90
Processing of metals by pressure. Forgings	В03	OST 1 90073-85
Tubes of non-ferrous metals and alloys	В64	OST 1 92048-90, OST 1 92048-76, TU 1-2-293-79, TU 1-4-062-87
Bars and shapes	В52	OST 1 92093-83
Castings, non-ferrous metals and alloys	В84	OST 5.9397-90

Chemical composition

Standard	Mn	Cr	Si	Ni	Fe	Cu	Al	Ti	Zn	Mg
GOST 4784-97	0.4-1	≤0.1	0.5-1.2	-	≤0.7	3.9-5	Rest	≤0.15	≤0.25	0.2-0.8
OST 1 92014-90	0.4-1	-	0.6-1.2	≤0.1	≤0.7	3.9-4.8	Rest	≤0.1	≤0.3	0.4-0.8

Al is the base.
According to GOST 4784-97 the chemical composition is given for the alloy AK8. The total mass fraction of titanium + zirconium ≤ 0.20%, the mass fraction of each other impurity (not regulated) ≤ 0.05%, the total mass fraction of other impurities ≤ 0.15%.
According to OST 1 92014-90 the chemical composition is given for the alloy AK8. Mass fraction of each other impurity (not regulated) ≤ 0.05%, total mass fraction of other impurities ≤ 0.10%.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	HB, MPa
Forgings for OST 1 90073-85. Mode T1: Quenching + artificial aging (indicated by the direction of samples)
≤75	-	≥355	≥4	≥120
75-250	-	≥355	≥4	≥110
≤75	-	≥410	≥8	≥120
75-250	-	≥385	≥6	≥110
≤75	-	≥390	≥6	≥120
75-150	-	≥390	≥6	≥110
≤75	≥315	≥430	≥10	≥120
75-150	≥295	≥410	≥8	≥110
Forgings for OST 1 90073-85. Mode T: Quenching + natural aging (indicated by the direction of samples)
≤150	-	≥365	≥8	≥110
150-250	-	≥355	≥7	≥110
≤150	≥245	≥385	≥10	≥110
150-250	≥235	≥375	≥8	≥110
≤150	≥235	≥365	≥8	≥110
≤150	≥245	≥385	≥11	≥110
The pressed bars normal strength in the delivery condition according to GOST 21488-97 (longitudinal samples)
150-300	-	≥430	≥8	-
8-150	-	≥450	≥10	-
Bars extruded high tensile strength in the delivery condition according to GOST 21488-97 (longitudinal samples)
8-300	≥335	≥460	≥8	-
Large-size extruded tubes according to OST 1 92048-76 on delivery
	≥294	≥412	≥8	-

Description mechanical marks

Name	Description
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
HB	Brinell hardness number

Physical characteristics

Temperature	Е, HPa	r, kg/m³	R, Mr. · m
20	74	2800	43

A description of the physical symbols

Name	Description
Е	The normal elasticity modulus
r	Density
l	Coefficient of thermal conductivity
R	UD. the resistivity

Technological properties

Name	The value
Weldability	The weldability of the alloy is satisfactory.
Machinability	The alloy has good machinability.

Alloy AK8 (1380)

Designation

Description