Aluminium alloys are metals composed mostly of Aluminium with additional alloying elements added to improve the capabilities of the basic Aluminium. These include improved strength, corrosion resistance, conductivity, and so on, or a combination of these characteristics. There are hundreds of Aluminium alloys that have been specifically created for these benefits. This article will compare 6061 Aluminium alloy with 7075 Aluminium alloy, two commonly used Aluminium alloys in the industry.

6061 Aluminum alloy

Type 6061 Aluminium is part of the 6000 class of Aluminium alloys, which contains alloys with magnesium and silicon as major constituents. Aluminium Alloy 6061 Sheet alloy has the following elemental composition: 0.6 per cent Si, 1.0 per cent Mg, 0.2 per cent Cr, 0.28 per cent Cu, and 97.9 per cent Al. Because of its copper concentration, type 6061 is sensitive to corrosion; however, this impact is not as strong as in other copper-laden alloys. 6061 Aluminium has excellent formability, excels in extrusion projects, and is easily joined by welding. Because of its moderately high strength and fair corrosion resistance, type 6061 Aluminium is an excellent general-purpose alloy with numerous applications in structural materials, welded assemblies, piping, fasteners, electronic parts, and other areas.

7075 Aluminum alloy

The 7075 Aluminium alloy belongs to the 7000 class, in which zinc is the major alloying ingredient, while auxiliary metals are sometimes employed as well. It is composed of 90.0 per cent Al, 5.6 per cent Zn, 2.5 per cent Mg, 0.23 per cent Cr, and 1.6 per cent Cu. Because 7075 contains less than 1% Cu, it is more susceptible to caustic conditions and lacks the excellent corrosion resistance of other Aluminium alloys. This is a necessary drawback since the high copper concentration contributes to the alloy’s extraordinary strength. This alloy is one of the strongest forms of Aluminium available, although it is difficult to shape and weld and is more quickly corroded. These disadvantages are offset by 7075 Aluminum’s outstanding strength, which shines in high-stress situations such as the aerospace sector, high-wear components, structural materials, and military applications.

Differences Between Aluminum 6061 and Aluminum 7075

  • Yield Strength– The yield strength is the greatest amount of stress that will not permanently (or only “elastically”) deform an alloy specimen. When the yield strengths of 6061 and 7075 Aluminium are compared, it is clear that 7075 Aluminium outperforms 6061 by nearly a ratio of two. This is due to the chemical makeup of 7075, as well as heat treatment. However, 6061 alloys are not considered weak, since their yield strength of 276 MPa is just slightly lower than that of some low carbon steels.

 

  • Elasticity– The modulus of elasticity of a material is a measurement of its resistance to permanent (or “plastic”) deformation. It may be used to define the “stiffness” of a material. When the moduli of these alloys are compared, there is a minor difference, indicating that these materials behave similarly when elastically deformed.

 

  • Thermal Conductivity– A material’s thermal conductivity is a measure of how well heat is carried through it (or how effectively it can “conduct” heat). A high thermal conductivity (as found in these metals) indicates that they conduct heat quickly and are not insulators. It should be noted that these figures are based on empirical experiments and can vary depending on heat treatment, alloy composition, and other variables. Because 6061 aluminums have a greater thermal conductivity in general, it is more suited for heat-dissipative applications (such as heat sinks and heat exchangers) than 7075 aluminums, however, the thermal conductivity of 7075 aluminum is still fairly excellent.

 

  • Melting Point– The melting point is the temperature at which an alloy will phase-change from solid to liquid, and it is stated in ranges owing to temperature variations, elemental compositions, and distinct phase states. Although being twice as strong as 6061 alloys, 7075 alloy melts at a little lower temperature. This value is important in heat treatment, where these temperatures are often required to evenly disperse the alloying elements into the base metal, or in high-temperature applications.

 

  • Electrical Resistivity– The electrical resistivity of a substance is a measure of how efficiently it resists the transmission of electricity. It is the inverse of electrical conductivity, which functions similarly to thermal conductivity but with electrical charge rather than heat. Both of these alloys have low resistivity, implying high conductivity, and are thus electrically conductive materials. In general, 6061 aluminum is better suitable for these applications because it is more commonly available, can be shaped and welded more easily, and is somewhat more conductive than 7075 aluminums.

 

  • Hardness– Hardness is an essential parameter because a harder material fails more easily through the brittle fracture, hence a compromise between hardness and ductility must be established. Both of these alloys are hard enough to sustain easy deformation while remaining ductile enough not to shatter/crack readily, making them both good construction materials. If hardness is required, 7075 aluminums should be used since it is typically tougher than type 6061 alloy.

 

  • Machinability– The machinability of a material is a measure of how it reacts to machining operations such as milling, cutting, die-casting, and so on, and is measured when machining a specific alloy using tooling speed, surface polish, and tool life. Machinability, like hardness, can be characterized in a variety of ways, hence this page includes a qualitative rating (excellent/good/fair/poor) to minimize misunderstanding. Both of these alloys are easily machined; however, 6061 aluminum is the favored choice if machinability is an issue. If machinability is a priority, other alloys such as types 2011, 2007, and 3003 should be preferred over these two.

 

The decision between titanium and aluminum may be simple. However, choosing between alloys of the same metal might be difficult. Your decision will be influenced by a number of factors, the most important of which is the intended use. Manufacturing conditions and prices are other important considerations. 6061 is a versatile alloy that may be used for a variety of structural components. It is beneficial when a large amount of machining is necessary, a large amount of welding is required on the item, corrosion is a worry, and the cost is the main consideration. On the other hand, when a high strength-to-weight ratio is required, 7075 aluminum is preferable. The plant will be exposed to a lot of heat, there will be a lot of friction, and the cost is less of an issue.

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Jagdish Metal

Differences Between Aluminum 6061 vs Aluminum 7075

by Jagdish Metal time to read: 4 min
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