Anodizing is an important industrial process that aids various applications. There are various types of anodizing processes that have developed over the decades.
What is Anodizing?
Anodizing is a process that increases oxidation on a metal’s surface through an electrochemical activity. It is a vital industrial process that protects metals and machinery components from corrosion and damage. Type I and type II anodizing processes are more popular in use throughout the world and across industries.
Type I anodizing is done using chromic acid while type II is achieved with sulfuric acid. One can argue that type I is better than type II. But both processes have their own uses.
It is done by treating the metal with the acid solution and running an electric charge through it. The process creates a coating of oxidation on the surface of the metal and offers it many new properties. Type I results in thin coating whereas in type II, it is thicker.
Most professional chromic acid anodizing expert also deal in type II or III processes.
The History of Anodizing
The earliest process for anodizing was achieved using chromic acid. The anodizing process became popular around 1920s when aluminum began to be used on a widespread scale especially in the shipping industry. Soon after, use of sulfuric acid was invented for anodizing aluminum. The benefits of anodizing made the process popular throughout the industrial world. These days other chemicals such as phosphoric acid are also used for anodizing process. But types I and II remain popular with industries due to their useful properties.
Slowly, anodizing began to be used for other applications other than making aluminum resistant to corrosion. Chromic acid made the metal nonconductive. So, it began to be used in insulating applications.
Other than aluminum, the anodizing process has been used on magnesium and titanium. But its application for aluminum is still the most widespread.
Type I anodizing is now mainly used in aircrafts and the aviation industry. It is used in landing gear where the metal can experience heavy stress. If you need a metal to use as an insulator then type I process can provide you with a good aluminum source to use.
Type II anodizing is used in computers, appliances, sporting goods, optical components, architectural materials, and military applications. You can find metal anodized with sulfuric acid in microwaves, refrigerators, and even televisions sets. It can now be found inside your smartphones.
In terms of sporting goods, metals processed with sulfuric acid are used in baseball bats, fishing tools, camping equipment, and golf carts. In terms of architectural use, it is used to make building components, storefronts, and roofing systems. It is also used to dye aluminum permanently.
Type III produces tough coating and used for application requiring sturdier metals. It also can be used as an insulator.
You can use anodized finishes in furniture, in art, and even contemporary jewelry. There is a lot of scope in how the process of anodizing is used to create metal surfaces that are studier, can be dyed, or used to create new products.
Type I produces waste that needs to be treated with greater care. It can lead to additional operational costs. Type II anodizing waste can be treated in more cost-effective ways.
Type II anodizing is also cost-effective to produce as it can be completed in less amount of time than chromic acid processes. The former requires less energy to produce oxidation on metal.
Chromic acid anodizing experts will agree that type I is not better than type II or vice versa. They are just different in terms of applications. Type II may score over type I in terms of low operational costs and waste treatment. But in certain applications, you can’t do without metals not treated with chromic acid. Most anodizing service providers offer different kinds of process.
Every day experts are coming up with different applications for anodized aluminum. The anodizing processes have become simplified and better. From heavy industries; one can now see use of anodized metals in everyday items that are in routine use around the world.