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Alca 5 vs. 6061 Aluminum: What Are the Differences?

The low density of aluminum makes it suitable for a wide range of manufacturing applications — 6061 aluminum and 5083 aluminum being the two most common aluminum alloys. While 6061 aluminum is an extruded alloy, 6061 aluminum sheet/plate is an alloy of aluminum, silicon, and magnesium which is strengthened by precipitation hardening. 5083 aluminum sheet displays exceptional strength as a non-heat-treatable alloy for commercial applications. A popular 5083 aluminum cast plate is Alca 5, a patented product of PCP Aluminum known for its excellent strength to help meet the most demanding applications.

Both 6061 aluminum and Alca 5 have unique characteristics; accordingly, understanding the differences between Alca 5 vs 6061 aluminum is essential for fabricators looking to make an informed decision on which aluminum alloy to use for their specific applications.

6061 Aluminum Properties and Characteristics

6061 aluminum contains magnesium and silicon as major alloying elements. These elements are known for adding strength to the alloy. Magnesium specifically improves corrosion resistance and weldability, whereas silicon lowers the melting point to avoid the hot tearing of aluminum. 6061 also contains copper (0.15%-0.40%) to further add mechanical strength and protect the alloy from artificial aging. Moreover, it has a relatively high quench sensitivity, which further lends to its strength and hardness.

Due to its low density, 6061 aluminum is comparatively softer than other alloys such as titanium and stainless steel, which is beneficial for the automobile industry in particular where designing lighter alternatives to heavier cars is a priority. A low density also contributes to 6061’s low melting point, which is ideal for hydroforming and quick plastic forming (QPF).

However, it’s important to note that the strength of 6061 aluminum can be increased through various heat treatment processes. Thus, it is available in various tempers, each with a different strength profile based on the type of heat treatment received.

Different 6061 tempers

  • 6061-F: As fabricated
  • 6061-O: Annealed
  • 6061-W: Solution heat-treated
  • 6061-Tx: Thermally treated

When 6061 comes into contact with air and water, it forms a protective layer over itself to fight against atmospheric corrosion. It’s an especially ideal choice for offsetting the harmful effects of nitric acid, ammonia, and ammonium hydroxide.

Alca 5 Properties and Characteristics

5083 aluminum contains chromium, manganese, and magnesium as some of its major alloying elements. This alloy displays good weldability, making it a preferable material for structures requiring high weld efficiency and maximum weld strength. 5083 aluminum has excellent corrosion-resistance against seawater and industrial chemicals; it’s highly suitable for marine applications. As the alloy can withstand extremely low temperatures without becoming brittle, it is also used in cryogenic environments.

Alca 5 aluminum is a 5083 alloy cast plate that’s best used for the fabrication of tooling and precision instruments. Concentrated amounts of magnesium protect against stress corrosion cracking, while the continuous horizontal casting process offers exceptional dimensional stability. Due to their high dimensional stability, Alca 5 plates barely deform and show rapid machinability. Alca 5 jigs and molds are highly sought-after in the industry for their stability and tolerance even at higher temperatures.

As it inherits the proprietary stress-relieved process of AA5083 aluminum, Alca 5 has low levels of internal porosity and does not require rough milling, finishing, or rework (unlike its alternative, MIC-6). This saves manufacturers a lot of additional machining costs.

Alca 5 displays excellent corrosion resistance against atmospheric conditions and good resistance against marine atmosphere conditions. The alloy also responds well to different types of welding, such as WIG/MIG and spot welding.

Alca 5 vs. Aluminum 6061: Differences at a Glance

Here’s a quick breakdown of the differences between Alca 5 vs. 6061 aluminum:

Property 6061 Aluminum Alca 5
Production method Flat-rolled or extruded Horizontal casting process
Form  Plate, bar stock, rounds Plate, block
Surface finish  60-90 RMS 20 RMS or better
Ultimate tensile strength 45 ksi 41 ksi
Yield strength 40 ksi 18 ksi
Shear strength 31 ksi 27.5 ksi
Brinell hardness 95 HB 70 HB
Corrosion resistance  Excellent Excellent
Machinability Average Excellent
Weldability Excellent Good
Application(s)  For structures and components where strength and corrosion resistance are required When precise tolerance and dimensional stability matter

Fabricators often opt for 6061 when designing low-budget, high-strength structural applications with reinforced corrosion resistance. On the other hand, Alca 5 alloys are best utilized as a base for machining tools that require high tolerance and dimensional stability during operations.

The mechanical strength of Alca 5 vs. 6061 aluminum is also an important consideration. Though both alloys nearly have the same tensile strength, 6061 has better yield strength than Alca 5. Yield strength represents the maximum load that can be applied. Unlike Alca 5, 6061 is used in structural applications where high yield strength improves its ability to withstand unexpected impact loads such as earthquakes.

As a porosity-free billet, Alca 5 shows exceptional machinability. A smooth surface is easily obtainable with the right tool and cutting speed. The machinability of 6061 depends on its temper type. For instance, the 6061-O variant is highly ductile and thus produces gummy chips during the machining process. But the 6061-T6 variant offers a good surface hardness after artificial aging and is easier to machine.

Precision-Cut Alca 5 and 6061 Aluminum From a Reputable Metal Supplier

Based in San Jose, CA, Industrial Metal Service carries a wide inventory of metals, including Alca 5 and 6061 aluminum, to meet your needs. We offer both new, mill-sourced metals as well as verified remnants to fit your budget requirements. Our industrial metal sawing services can further save your team time and resources—we can cut your metals to precision and deliver them anywhere in the country with no minimum order policy.

Contact us today to learn more about the differences between Alca 5 vs. 6061 aluminum and which one makes sense for your project and budget. We look forward to working with you!

Published by IMS Team

Industrial Metal Service has decades of experience and over 1.1 billion pounds of metal sold and recycled. Our founder, Jeff, has spent his life in the industry and prides himself on offering fair, efficient, trustworthy, knowledgeable, outstanding customer service. We offer metal salesmetal recycling pickup service, and other associated services, such as precise metal sawing, machinery teardown, and warehouse cleanupGive us a call and we’ll get it done.