What Exactly Is Black Oxide Coating And What Does It Do?
Black oxide coating is the process of coating ferrous materials, stainless steel, copper, copper based alloys, zinc, materials with a chemical coating process. It takes products, and it coats them in iron oxide. This provides many benefits. First, it reduces light reflection. This is beneficial because for products such as IR sensors, UV sensors, passive infrared detectors, etc. excess or reflected light can completely alter the results. Also, black oxide coating is beneficial because it adds thickness to steel, even though it’s microscopic, it helps maintain the sharpness of things like drills or screwdrivers. Also, it helps reduce corrosion and friction due to the oil or wax present. The wax or oil also allows for the material to be water resistant.
The Full Process Of Black Oxide Coating
There are three types of black oxide coating: hot black oxide, mid-temperature black oxide, and cold black oxide. First, hot black oxide coating. This includes a hot bath of nitrites, nitrates, and sodium hydroxide. The ferrous material is dipped in the bath which turns its surface into magnetite. After, the material is dipped into three tanks which contain alkaline cleaner, water, and caustic soda which is what eventually turns the material black. Finally, the material is dumped into the oil or wax which is the coating material. Now onto mid-temperature black oxide coating. This is pretty much the exact same as the hot coating technique, but the only difference is the temperature at what the product blackens at. This can be more beneficial because it doesn’t release caustic fumes due to the fact it is below its boiling point. Finally, cold coating. This process is different because it doesn’t involve oxide conversion. It uses deposited copper selenium to alter its product. It is the simplest way to coat a material, but it rubs off easier and provides less resistance. Black oxide coating can be used for many materials such as copper, zink, and stainless steel. However, each material requires a different technique due to their- density and chemical makeup. These processes are very complex and require professionals to carry out.
Why Should You Choose Black Oxide Coated Products?
In the end, coated products last longer. They don’t rust or corrode as easily as other materials. Their wax coatings make them resistant to water which is the main source of rust. Also, this wax coating allows the cleaning process to be much quicker. Since you don’t have to worry about harmful substances reaching the metal core due to the wax, you don’t have to spend as much time cleaning the item. Black oxide coating also gives your tools a sharper edge which won’t dull over time. This provides more accuracy and reliability with your product.
Acktar Black Vs. Black Oxide
Black Oxide is deposited on materials mainly to protect against corrosion and also has somewhat lowered reflectivity. Acktar Black coatings are used to meet optical performance requirements.
Where optical performance is the main requirement Acktar Black coatings are far superior. In addition to their overall superior low-reflectivity performance Acktar Black coatings can be tailored for specific spectral requirements. Black Oxide coating processes involve ecologically dangerous baths while the Acktar coating process is completely ecologically clean.
The oil or wax impregnates in black oxide coatings make them unsuitable for vacuum or elevated temperature applications because of outgassing considerations. For the same reason these coatings cannot be space qualified.
Acktar Black can be deposited on essentially all engineering materials – including polymers and ceramics – while Black Oxide is limited to a few metals – mainly ferrous and copper based materials. Unlike Black Oxide – Acktar Black can be tailored – within limits – to electrical conductivity requirements.