Anodising is an electrochemical process where metals are toughened by treating them to thicken the oxide layer on the surface. Here, the microscopic texture and crystal structure of the surface are changed to increase resistance to corrosion and wear when metals are exposed to marine, industrial and humid atmospheres. The anodized surface www.badgeranodising.co.uk/services/anodising-and-coloured-anodising/ provides better adhesion for glues and paint primers as compared to bare metal. Thick paint coatings are normally porous, and a sealing process is necessary to enhance resistance to corrosion and wear.
This process is normally used in the treatment of aluminum. It penetrates the surface to increase the thickness of the oxide coating. This becomes extremely rigid. The appearance of the metal is also improved.
When combined with other special procedures and dyes, the metal ends up looking like copper, pewter, bronze or stainless steel. This kind of anodising is made possible through the use of various dyes to produce permanent pigmentation. Any color can be used, from clean to black to bright colors.
Before any metal is anodized, its surface has to be cleaned and www.badgeranodising.co.uk/services/metal-polishing-finishing/ pre-treated. An alkaline is normally used to remove oil, grease and dirt from the surface. Surface pre-treatment involves a two-stage process; etching and brightening where a combination of nitric and phosphoric acids is used to brighten the surface. The main procedure involves immersing the metal in an electrolyte wash and passing direct current through it (the metal) till the intended thickness level is attained.
There are many advantages of anodising. Metals that have undergone this process are normally harder than their powder-coated counterparts. Anodized metals can also withstand abuse and UV exposure better. To achieve the same level of toughness, one would have to coat with a super-durable powder. When done inorganically, anodising also has better color retention.
Some people also prefer anodized metals to their powder coated counterparts because they deem the former to be more metallic. Though there are some powders which resemble anodising, there’s still a noticeable difference. Unlike conventional paint, an anodic coating bonds by chemically changing the surface of the metal. However, it doesn’t interfere with the matrix and as such does not peel.
The ability to retain color and glue makes anodized metal ideal for car parts, decorative pieces and curtain rings. Such metals are less likely to crack or peel. Anodized metals are not only easier to clean as with bead blasting www.badgeranodising.co.uk/services/bead-blasting/, but they are also resistant to heat. Cookware pieces are normally made of aluminum that has undergone this process. The utensils spread heat better, last longer and are resistant to rust. They also don’t react with acidic foods such as citrus fruit, tomatoes and vinegar.
In some cases, there are mechanical aspects that need consideration before anodising can be done. The surface will be raised, since the oxide layer occupies more space than the bare metal. Generally, this is not of much consequence except when there are small, threaded screw holes. These have to be chased with a tap so that the original dimensions are restored. For unthreaded holes, a slightly larger size is used to allow for dimension change.