What is 6063 Aluminum?Properties, Strength ,Uses and Application?

What is 6063 Aluminum？

An 6063 Aluminum is any metal that has been improved by adding trace amounts of other metallic elements to it. Aluminum metal is one of the most popular base metals to alloy because of how common it is and its great material properties. There are numerous aluminum alloys, each with different types and compositions of alloying elements, and they each possess some benefit in terms of strength, workability, weldability, etc. To distinguish these alloys from one another, the Aluminum Association has developed a naming scheme that organizes aluminum alloys based on alloying elements and material properties, using a four-digit “name”. The first digit of this name indicates the series of alloys, which are mainly divided by alloying elements; for example, the focus of this article is 6063 aluminum which is of the 6xxx alloys, or those that use magnesium and silicon to enhance the base aluminum. This alloy’s properties, strengths, and applications will be explored through this discussion, so as to better understand how useful this material can be for designers.

Physical Properties of 6063 Aluminum

6063 aluminum alloy is heat treatable, weld-able, good at resisting corrosion and easily formed. It is a top choice for extrusion because of its properties, as it is easily pushed through a die into many fixed-cross sectional shapes. This alloy is distinguished from another popular 6xxx series alloy, 6061 aluminum alloy, by its percentages of alloying elements (feel free to read all about 6061 alloy here). 6063 aluminum’s compositional breakdown is 0.7% Mg, 0.4% Si, and 98.9% Al, which is slightly more basic than 6061 aluminum’s composition. Note that these numbers fluctuate based on manufacturing desires or natural impurities, within certain tolerances. Type 6063 aluminum’s density is 2.7 g/cm3 (0.0975 lb/in³) and is about the same as pure aluminum metal. There are only slight differences between 6061 and 6063 aluminum, but the most noticeable of them is that 6063 is less strong but more easily formed, making it invaluable for complex, extruded projects.

Corrosion Resistance

All aluminum types react with air or water, as most metals do, but aluminum alloys actually gain strength instead of degrading. A protective layer of oxide attaches to the outside layer of aluminum, which provides a barrier to anything that might interact with the chemically-active aluminum metal. This provides a fair amount of resistance to corrosion, and the 6xxx alloys are known to have good chemical resistance. Most corrosive effects to 6063 aluminum are generally negligible under normal atmospheric conditions, which cannot be said for other common materials such as carbon steel. 6063 aluminum is also more resistant than its brother (type 6061) because it contains much less copper, an element that increases susceptibility to corrosion. 6063 is chemically inactive to concentrated nitric acid, ammonia, ammonium hydroxide, and certain soils, though this is hard to generalize due to the variance of soil compositions. 6063 alloy can be coated with a protective layer (see our article all about 2024 aluminum for information on cladding) to make it even less affected by corrosion.

Mechanical Properties

Table 1, found below, summarizes the important mechanical properties for 6063 aluminum. These include the ultimate, yield, and shear strength, as well as the modulus of elasticity and shear modulus. These values depend on how the alloy is heat-treated or strengthened using the heat-treatment process (see our article all about 2024 aluminum to get a more in-depth understanding of this procedure). Each “temper” has its own distinct qualities, but this article will only focus on the 6063-T6 temper for simplification.

The tensile yield strength is a measure of how much tensile (pulling) stress a piece of 6063 aluminum can take before plastically (or permanently) deforming. It is imperative for architectural applications because the amount of stress on a 6063 alloy part should never exceed this value, or the building collapses. The yield strength for 6063 aluminum is 214 MPa (31,000 psi), which is only slightly less strong than its 6061 counterpart.

The ultimate strength is the maximum amount of stress during plastic deformation, usually reached sometime before a test specimen of aluminum breaks in two (known as the “fracture point”). This value is usually not specified, but it is useful to know with extrusion alloys like 6063 because it must be plastically deformed, but not broken. The ultimate strength for 6063 aluminum alloy is 241 MPa (35,000 psi).

Shear strength measures the maximum amount of shearing stress a material can undergo before plastically deforming. Shearing stress is any stress that imparts opposing forces along a plane; think scissors cutting paper. When the opposing forces of the scissor blades meet the thin cross-section of the paper, the paper fails in shear (or “cuts”) due to the shear stress it experiences from the blades. Shear strength is useful when using alloys in sheet metal stamping and bar cutting, so as to better understand how the material will react to this kind of shearing deformation. For 6063 aluminum alloy, the shear strength is 152 MPa (22,000 psi), which is low enough to allow for this kind of machining.

The modulus of elasticity and shear modulus define the material’s resistance to elastic (or non-permanent) deformation. They are calculated from the elastic regions of stress-strain curves (read more on this topic in our article all about 3003 aluminum alloy), and are good indicators of general material strength. For 6063 aluminum, its modulus of elasticity and shear modulus are 68.9 GPa (10,000 ksi) and 25.8 GPa (3,740 ksi), respectively. These values are about the same in 6061 aluminum, and this makes intuitive sense because alloys of the same series should respond to elastic deformation in similar fashions.

Summary of mechanical properties for 6063 aluminum alloy.