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Views: 50 Author: Site Editor Publish Time: 2024-03-28 Origin: Site
Many metals quickly rust if not protected by paint, plating, or similar coatings, while aluminum and stainless steel react with oxygen in the air to form a thin protective layer called a passivation layer. This will be discussed in detail later.
We won't delve into the electrochemical mechanisms that lead to various forms of rusting—it's a complex topic. However, it's worth noting that it happens faster in humid air and water, especially in the presence of saltwater, causing even the tallest buildings and strongest bridges to eventually collapse.
The good news is there are various corrosion-resistant metals to choose from. Here are several commonly used in manufacturing along with some application examples:
The metal is an excellent choice for many applications. Its numerous alloys are strong, lightweight, non-magnetic, and conductive, making it suitable for products ranging from cookware to mechanical hardware, electronic casings, and scientific instruments.
We offer five types of aluminum suitable for CNC machining and one for 3D printing. 6082-T651, similar to 6061, is a versatile alloy easy to mill, turn, laser cut, bend, shape, and weld. 7075-T651 and 7075-T7351, both used in the aerospace industry, with the latter being stronger and more durable. 5083-H111 is more corrosion-resistant due to its higher magnesium content. 2024-T351 is an aerodynamic material specifically used for components under tension, known for its fatigue resistance.
For 3D printed parts, there's AlSi10Mg, a tough aluminum long used for castings. Additionally, the thin protective layer mentioned earlier is called aluminum oxide, a very hard compound found in many grinding wheels. If you desire a tougher coating, you can also turn to anodizing.
First, I want to mention that this lightweight metal is very expensive. If that's acceptable to you, please continue reading! Metallurgists will tell you that it's as strong as steel but only half the weight, with twice the strength of aluminum but only one and a half times the weight. Titanium is also one of the most corrosion-resistant metals, thanks to the titanium oxide coating it forms in the presence of oxygen.
We rightly label titanium Ti6Al4V as the "workhorse alloy" because it's widely used in medical implants, aircraft engines, power generation facilities, sports equipment, and various other applications where this crucial alloy is processed and 3D printed.
The protective layer on this steel alloy comes from chromium oxide. This is because chromium is the element that imparts all stainless steels with their name. Grade 304 or A2 is a good "general-purpose" grade used for cutlery and freshwater applications. Grade 316 or A4 stainless steel is a tougher, more heat-resistant, wear-resistant, and corrosion-resistant grade, thanks to 2% molybdenum. It's often referred to as marine-grade because it can resist saltwater corrosion. Each of these products meets the requirements of the "low carbon" grade indicated by "L," such as 304L and 316L. They are slightly softer and easier to weld. Finally, here's another aerospace favorite, 17-4 PH. Unlike the 300 series stainless steels, 17-4 can be hardened through heat treatment, so it's often found in gas turbines and aircraft components.
This alloy shares many mechanical properties with stainless steel but with slightly higher strength and greater wear resistance. Due to its biocompatibility, you might have a cobalt-chromium wedding ring on your finger, dentures in your mouth, or replacement joints in your knee or hip, although cobalt-chromium is also common in many industrial applications. While the stainless steels just listed are regulars on ZONZE CNC milling machines, lathes, and Direct Metal Laser Sintering (DMLS), cobalt-chromium high-temperature alloy Co28Cr6Mo is currently limited to DMLS 3D printing.
This is another unique product exclusive to DMLS. This is because processing this high-temperature alloy is highly challenging, but it's easily 3D printed into parts measuring 400 mm × 800 mm × 500 mm on some of our printers. Like 17-4 stainless steel, Inconel 718 exhibits precipitation hardening but contains a significant amount of nickel as well as around 5% refractory metals niobium and molybdenum. This accounts for its robust strength and high heat resistance, making it the preferred material for components enduring temperatures up to 700°C (1,300°F) and extreme mechanical loads. Additionally, it can resist various forms of corrosion.
This is an alloy of copper and zinc, positioned at the opposite end of the machinability chart from chromium-nickel-iron alloys, titanium, and cobalt-chromium alloys. However, this does not diminish its value, especially for those seeking corrosion-resistant, easy-to-machine metals. It's suitable for pipe fittings and adapters, bearings, radiators, threaded fasteners, and any other parts requiring high electrical and thermal conductivity. ZONZE stocks two types of brass. The so-called free-cutting brass C360 (Cz121 or CuZn36Pb3). Brass is an attractive alternative for turning and milling parts, boasting many admirable qualities, especially its pleasing appearance.
Finally, in our corrosion-resistant lineup, there's copper—C101. It's one of the most electrically and thermally conductive materials on Earth. In terms of its various applications, copper overlaps to some extent with brass but is generally easier to form, less malleable, and more expensive. It's an excellent choice for high-performance heat exchangers and electronic or electrical applications (such as EMI shielding). Due to its antimicrobial properties, copper is increasingly being used in hospital equipment.
Seen enough? It should be clear by now that we have plenty of corrosion-resistant metals available for your next project choice. Whether through CNC turning, milling, or metal 3D printing, there are plenty of methods to quickly transform these metals into precision parts.
Before we let you go, it's also worth noting that there are many engineering-grade polymers to meet your needs, and metals prone to rusting like low carbon steel and EN8 alloy can be made more weather-resistant through appropriate surface treatments. Note that such treatments may also be necessary for some of the metals discussed earlier. For instance, aluminum typically requires anodizing, much like stainless steel materials should undergo passivation to enhance corrosion resistance.
If you have any questions, feel free to email us. Our application engineers are always available to assist at info@zonzescm.com.
