Metallic alloys give designers many options when starting their projects, and choosing the correct one can be daunting to the uninitiated. An alloy is an improved engineering material made by imbuing a base metal with small amounts of different metals, called alloying elements. One of the most popular base metals to alloy is aluminum. Each unique alloy has been given a four-digit name, where the first digit designates what are the basic alloying elements of that group, known as the series number. This article will investigate two alloys from the 5xxx and 6xxx series, or those alloys which contain magnesium and magnesium with silicon, respectively. These alloys are 5052 and 6061 aluminum alloys, and they are both invaluable materials in their respective domains (more information on these alloys can be found in our articles all about 6061 and 5052 aluminum). By examining the strengths, uses, and properties of these alloys and then comparing them, this article will show how to specify an alloy for a job and how each aluminum alloy has their own merits in an application.
6061 Aluminum alloy
6061 aluminum alloy is widely known and far-reaching, being found in almost every corner of the market today. Its popularity is the result of its good corrosion resistance, weldability, machinability, and moderate-to-high strength. Its chemical composition is 0.6% Si, 1.0%Mg, 0.2%Cr, 0.28% Cu, and 97.9% Al, though these numbers can slightly differ based on impurities and manufacturing methods. 6061 aluminum’s density is the same as pure aluminum (2.7 g/cm3, 0.0975 lb/in3), and it can be strengthened using the heat-treatment process (for more information about this process, visit our article all about 2024 aluminum alloy). Some of the common tempers of 6061 aluminum are 6061-T6 and 6061-T4. This alloy has a good combination of strength, workability, and resistance to wear, making it an ideal general-purpose alloy. While it does not excel in any one area, 6061 aluminum is a“jack-of-all-trades”material and has been used in structural materials, marine frames, heat sinks, chemical equipment, and even soda cans.
5052 Aluminum alloy
5052 aluminum has a higher modulus of elasticity than 6061 aluminum (70.3 GPa VS. 68.9 GPa), which explains why it excels as a forming alloy. 5052 aluminum's larger modulus of elasticity and its lower yield strength allow 5052 aluminum to be shaped and worked without much risk of breakage.
5052 aluminum alloy has some of the best welding characteristics, has great finishing qualities, has excellent saltwater corrosion resistance, but is not easily machined. This alloy is also not heat-treatable and can only be strengthened using the work-hardening process, with 5052-H32 being the most common procedure (for more information on work-hardening, feel free to visit our article all about 5052 aluminum alloy. Type 5052 aluminum is also considered the strongest of the non-heat treatable alloys. For these reasons, 5052 aluminum works exceptionally well as sheet and plate metal, combining excellent formability and weldability with increased strength. Its density is slightly lower than pure aluminum at 2.68 g/cm3 (0.0968 lb/in3), and its chemical composition is 2.5%Mg, and 0.25%Cr, and 97.25% Al. 5052 aluminum does not contain any copper, which means it is not as susceptible to salt water corrosion as other aluminum alloys, making it a perfect choice for marine applications. It also is often used in electronic enclosures, hardware signs, pressure vessels, and medical equipment.
Comparing 6061 & 5052 Aluminum alloys
6061 and 5052 aluminum alloys serve different purposes, and the material properties found in Table 1 will provide a brief explanation as to why this is the case. Generally, 6061 aluminum is best served for machining, while 5052 is used for sheet metal and welding applications, and this is a direct result of the qualities of each alloy. These material properties were taken from 6061-T6 and 5052-H32 hardened aluminum alloys, but know that each strengthening process has its own unique set of values. A brief explanation of each value will follow, but they are summarized in Table 1 for easy viewing.