Metal workpieces generally undergo different machining and fabrication processes so that they can generate different types of products. Once these products are produced, manufacturers would often subject them to a wide array of surface finishing processes to effectively enhance their appearance, strength, and other significant qualities.

Surface finishing, as previously stated, can alter and improve the appearance, strength, and other properties of finished metal products. It can be done by different processes. Some of them can be conducted mechanically, while others are done through either chemical or electrical means.

One surface finishing that is done by chemical means is black oxide coating. It is typically conducted on products made from ferrous metals, allowing them to obtain significant property improvements.

The Process of Black Oxide Coating

The black oxide coating is a surface finishing process that introduces a protective barrier to ferrous products. This specific process is typically done by dipping the mentioned products into an alkaline salt solution, allowing the surface of these products to chemically react to the solution. The solution that is being utilised by this process can vary depending on the properties of the metal products. It may be applied at room temperature. It may also be done in either cold or hot processing methods. Some applications might likewise require components to be pre-treated. 

Once the metal products interact with the solution, magnetite is generated on their surfaces, creating a protective barrier that will keep them safe from moisture and other damaging elements. The black colour of the magnetite is the main reason behind the name of this surface finishing process.

Different applications can maximise the process of the black oxide coating. For one, this process can be used on small moving parts such as gears, tools, and machine components. Black oxide coating can likewise be utilised in military applications, surgical instruments, and architectural assemblies.

Advantages of Black Oxide Coating

What makes black oxide coating great for some applications is that it can protect metal products from corrosion. Due to the development of magnetite on the surface of the products, it can easily protect them from moisture and elements that can generate corrosion. The process can even prevent hydrogen from infiltrating and damaging the products. It can likewise avoid the production of white corrosion.

Another advantage of black oxide coating is that does not add significant thickness to the dimensions of metal products. Since the process is done chemically, minimal dimensional changes can be expected to the processed products. This advantage alone makes the process great for small and intricate products.

Ultimately, black oxide coating can be beneficial for some applications as it can boost the appearance of metal products. The protective coating of the magnetite prevents the products from peeling, flaking, chipping, or rubbing off, preserving their appearance effectively. The dark black colour coating likewise makes the metal products appealing for some applications. This colour can even minimise eye fatigue and light glare that can distract a lot of people.

To find out more about black oxide coating, just contact us at Alpha Detroit Heat Treatment.