The Distinctive Characteristics of Aluminum 3003 and 6061

alloy

The most prevalent metal on Earth, aluminum, provides material scientists with numerous opportunities to experiment with it during the alloying process.

Alloys are metals created by mixing additional metallic elements with a base metal to give them improved material properties (strength, resistance, workability, etc.). The Aluminum Association Inc. has categorized these alloys into series based on the various forms that aluminum alloys can take depending on their alloying elements. This article focuses on the 3xxx and 6xxx series, which have four-digit names.

The two alloys in question, 6061 and 3003 aluminum, are among the most widely used types of aluminum and initially appear to be equivalent. With a focus on their benefits and drawbacks, this article compares the material properties of these two alloys in an effort to distinguish between them. To assist designers in making better material decisions for their projects, this article will define the applications that both of these alloys are best suited for through this discussion.

Alloy 6061 aluminum
Aluminum 6061 is renowned for its high strength, excellent weldability and machinability, and good corrosion resistance. The strength of 6061 aluminum makes it particularly useful for structural materials because it prevents tall buildings from toppling over. Magnesium and silicon are the primary alloying elements in 6061 aluminum, as they are in the other 6xxx alloys, and they are what give it its advantageous strength characteristics. The alloying components in 6061 aluminum are divided as follows: Its composition includes 0.6% Si, 1.0% Mg, 0.2% Cr, 0.28 % Cu, and 97.9% Al. Its density (2.7 g/cm3, 0.0975 lb/in3) is similar to that of pure aluminum. The heat treatment process increases the strength of 6061 aluminum, which is frequently found in T6 and T4 tempers. Due to its advantages, 6061 aluminum is a fantastic general-use alloy and can be used in a variety of applications. It is a popular option for welded assemblies, building frames, and any structure that needs a rock-solid skeleton and is available in most machine shops. Please feel free to read our article about 6061 aluminum alloy for more details on this metal.

Aluminum alloy 3003
One of the most popular types of aluminum on the market right now is the 3003 aluminum alloy, and for good reason. It accepts a good finish, forms well, welds easily, has a medium strength, and resists corrosion. Because of these qualities, this metal works well in a wide range of applications, which is why it is the most widely used general-purpose aluminum alloy. Manganese serves as the primary alloying element in 3003 aluminum, which belongs to the 3xxx series. Its chemical make-up is 0.12% Cu, 1.2% Mn, and 98.6% Al (note that these numbers change based on a number of factors, and only provide a general breakdown). The density of 3003 aluminum, which is similar to pure aluminum at 2.73 g/cm3 (0.0986 lb/in3) and does not change as a result of heat treatment, is 0.0986 lb/in3. Instead, this alloy, which typically comes in 3003-H18 and 3003-H22 tempers, can be strain-hardened to increase its strength. Despite not being particularly robust, 3003 aluminum finds many uses in the food and chemical industries as a highly malleable yet durable material.

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The strength of 6061 aluminum is the main justification for picking it over 3003 aluminum. This is demonstrated by contrasting their yield strengths, which represent the minimal amount of stress required to permanently deform these materials. Given that any permanent deformation will result in structural instability (and frequently failure) in a building, the yield strength is a useful metric for structural parts. The alloying components (magnesium/silicon) and the ability to be heat-treated give 6061 aluminum its increased strength. If strength is a top priority, 6061 aluminum is the only material to consider; it is a strong, more durable alternative to mild steels and is unquestionably stronger than 3003 aluminum.

Similarly, the increased bearing yield strength of 6061 aluminum indicates that it is stronger when joined with bolts and screws (386 MPa VS. 262 MPa). When two plates are joined together by a screw that passes through a hole in both plates, the bearing yield stress is the lowest stress that will cause the joint to deform. The bearing strength is a useful indicator of how a material will behave when joined because these joints can stretch or crack if the metal pieces are subjected to excessive force. Because 6061 aluminum has a much higher bearing yield strength than 3003 aluminum, it makes intuitive sense and also helps to explain why 6061 aluminum is frequently used in scaffolding and building skeletons. Although 6061 aluminum will last longer, 3003 aluminum will still hold up if many parts are riveted or connected by holes.

The shear strengths of these materials are excellent illustrations of the idea that strength is not always desirable. A material’s resistance to shearing stresses, such as those caused by cutting, stamping, or any other arrangement where two opposing forces collide at a cross-section, is measured by its shear strength. This can be easily understood by picturing paper being cut with scissors, where the two opposing blades shear, or “cut,” the paper through its thinnest dimension. As a result of its lower shear strength than 6061 aluminum, 3003 aluminum is actually advantageous because it is simpler to cut from sheet metal (207 MPa VS. 110 MPa). These qualities, along with its excellent formability, make 3003 aluminum particularly versatile in forming applications and are frequently cited as reasons to choose it over other alloys.

A material’s hardness rating describes how external forces will impact the material by describing how the surface reacts to local indentation caused by things like scratching, polishing, and penetration. Using indentation machines, engineers have developed various hardness scales that describe how materials react to indenting forces. A commonly used scale for measuring hardness is the Brinell scale, which ranges from 10 for soft metals like copper to 1550 for materials like glass. These alloys have a moderate degree of hardness, with 6061 aluminum having a harder hardness than the other (95 vs. 55), which improves machinability but impairs surface finish. 3003 aluminum can have a chrome finish, which is aesthetically pleasing and simple to clean, despite being more easily indented. As a result, 3003 aluminum is frequently used in food trucks because its reflective surfaces are easy to clean and do not accumulate dirt. If scratch resistance is a concern, 6061 aluminum is preferable to 3003, but 3003 shines (literally) brighter when it comes to finishing and polishing.

Due to its reputation as one of the best machining alloys, 6061 aluminum can be found in almost all machine shops. The ability of a metal to be tooled from stock metal is known as machinability, and this article uses a qualitative evaluation (excellent/good/fair/poor) to show the reader what alloys are typically machined. There are scales that measure machinability, but they typically only apply to machinists searching for the best tool for the job and are not helpful to the typical designer. The best aluminum for machining is 6061 because it can be worked and takes finishes well, while 3003 aluminum is typically used for sheet metal forming. Aluminum 3003 can also be machined, but 6061 is generally a better option due to its other beneficial characteristics.


Post time: Dec-12-2022