Aluminum alloy Material properties ( 2 )

Material properties
The aluminum alloy has low density, but high strength, close to or exceeds high-quality steel, good plasticity, can be processed into various profiles, has excellent electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in industry and is used second only to steel. . Some aluminum alloys can be heat treated to achieve good mechanical properties, physical properties and corrosion resistance. Hard aluminum alloy belongs to AI-Cu-Mg system, generally contains a small amount of Mn, which can be heat treated and strengthened. It is characterized by high hardness but poor plasticity. Super-hard aluminum is a Cu-Mg-Zn system, which can be heat-treated and strengthened. It is the highest strength aluminum alloy at room temperature, but has poor corrosion resistance and high temperature softening. The wrought aluminum alloy is mainly an Al-Zn-Mg-Si alloy. Although it has many kinds of elements, it has a small content, so it has excellent thermoplasticity and is suitable for forging, so it is also called forged aluminum alloy. [2] 
Material structure
The density of pure aluminum is small (ρ=2.7g/cm3), about 1/3 of iron, low melting point (660°C), aluminum is face-centered cubic structure, so it has high plasticity (δ: 32~40%, ψ: 70~90%), easy to process, can be made into various profiles and plates, and has good corrosion resistance. However, the strength of pure aluminum is very low, and the annealing state σb value is about 8kgf/mm2, so it is not suitable as a structural material. Through long-term production practices and scientific experiments, people gradually strengthened aluminum by adding alloying elements and applying heat treatment, which resulted in a series of aluminum alloys. The alloy formed by adding certain elements can have higher strength while maintaining the advantages of pure aluminum, and the σb value can reach 24 to 60 kgf/mm2, respectively. This makes its "specific strength" (the ratio of strength to specific gravity σb / ρ) outperforms many alloy steels and becomes an ideal structural material, widely used in machinery manufacturing, transportation machinery, power machinery and aviation industry, aircraft fuselage , skins, compressors, etc. are often made of aluminum alloy to reduce their own weight. The use of aluminum alloy instead of steel plate welding can reduce the structural weight by more than 50%.
 

Typical Mechanical Properties
Aluminum alloy grade	Tensile Strength(25°C MPa)	Yield Strength(25°C MPa)	hardness500kg force10mm ball	Elongation 1.6mm(1/16in) thickness
5052-H112	175	195	60	12
5083-H112	180	211	65	14
6061-T651	310	276	95	12
7050-T7451	510	455	135	10
7075-T651	572	503	150	11
2024-T351	470	325	120	20

Typical Physical Properties
Aluminum alloy grade and status	Thermal expansion coefficient (20-100℃) μm/m·k	Melting point range (℃)	Conductivity20℃(68℉) (%IACS)	Resistivity20℃(68℉) Ωmm2/m	density(20℃)(g/cm3)
2024-T351	23.2	500-635	30	0.058	2.82
5052-H112	23.8	607-650	35	0.050	2.72
5083-H112	23.4	570-640	29	0.059	2.72
6061-T651	23.6	580-650	43	0.040	2.73
7050-T7451	23.5	490-630	41	0.0415	2.82
7075-T651	23.6	475-635	33	0.0515	2.82

Chemical Composition Limit Of Aluminum
alloy Brand	silicon )Si	Iron Fe	copper ) Cu	manganese )Mn	magnesium )Mg	chromium)Cr	Zinc)Z	titanium)Ti	Other		Aluminum
									Each	Total	Minimum value
2024	0.232	0.5	3.8-4.9	0.3-0.9	1.2-1.8	0.1	0.25	0.15	0.05	0.15	margin
5052	0.25	0.4	0.1	0.1	2.2-2.8	0.15-0.35	0.1	--	0.05	0.15	margin
5083	0.238	0.4	0.1	0.3-1.0	4.0-4.9	0.05-0.25	0.25	0.15	0.05	0.15	margin
6061	0.236	0.7	0.15-0.4	0.15	0.8-1.2	0.04-0.35	0.25	0.15	0.05	0.15	margin
7050	0.235	0.15	2.0-2.6	0.1	1.9-2.6	0.04	5.7-6.7	0.06	0.05	0.15	margin
7075	0.236	0.5	1.2-2.0	0.3	2.1-2.9	0.18-0.28	5.1-6.1	0.2	0.05	0.15	margin