Aluminium Corrosion and the Corrosion of Metal explained.

So what is Corrosion? Corrosion by definition can be considered a chemical reaction that occurs in metal.

Aluminium Corrosion

For this article the metal in question is aluminium, a very reactive metal with a unique set of electromechanical properties.

This said it can also be considered a passive metal, explained by the contradictory processes that occur during a reaction.

On the one hand raw aluminium will interact with oxygen and water to form a consistent surface oxide layer. This can even be considered early stage corrosion but this layer has a ‘protective’ quality preventing any further rusting of the metal in it’s environment.

Back to Aluminium being a reactive metal, which it is. Very reactive. It’s the main ingredient in of choice in the space shuttles propulsion rocket fuel.

You may also seen the reaction between water and aluminium, high amounts of energy are released.

Types of Corrosion

Most noble metals will be vulnerable to corrosion. Aluminium can corrode several ways. This understanding can often make the difference in discovering an effective aluminium corrosion treatment.

Atmospheric Corrosion.

By far the most common culprit it is also the oldest being the result of exposure of metals to increased humidity and moisture. Sometimes this hazard is referred to as damp, wet or dry corrosion.

It accounts for most damages and product defects by weight.
This is a particular problem in the export packaging world where shipping goods worldwide can be hazardous due to different climates and atmospheric conditions.

Naturally it will vary greatly from location to location depending on air pollutants and the metals proximity to natural bodies of water like lakes and oceans.

Galvanic Corrosion

This type of corrosion is discussed in more detail here but it accounts for the largest number of aluminium corrosion problems.

This occurs when the aluminium alloy is connected electrically to a more reactive noble metal with both being in contact with an identical electrolyte.

Uniform Corrosion

Also known as general corrosion or general rust. Occurs where PH levels are either excessive (acid) or too low (alkaline).

When this happens the aluminium oxide surface layer becomes unusable and un protective.

Crevice Corrosion

This type of corrosion requires the formation of a gap or crevice of some kind.

This can most easily be demonstrated in the situation where corrosion forms between a bolt and the metal part it is bolted to.

This happens over time when saltwater or moisture is allowed into this crevice it will eventually be absorbed by the aluminium due to the process of precipitation.

There are many more lesser known types of corrosion including microbiological induced corrosion, filiform corrosion, corrosion fatigue, stress corrosion cracking, exfoliation corrosion and intergranular corrosion.

Aluminium Corrosion Removal

The typical approaches for corrosion removal are either topical application or immersion in a bath.

Topical is recommended for very light surface rust and can be done with a sponge or cloth.

More often than not though any client looking to invest in aluminium corrosion treatment will have to immerse the metal in a bath. A normal bucket can be used here.

Clean your metal free of any dust or debris first and then carefully place in your bath.

Lightly corroded items can be rust free in as little as 30 minutes whilst more heavy build up may require an overnight soak.

Aluminium Corrosion Treatment

As both a preventative measure and a corrosion remover we recommend the use of Corrosion X™ range of high performance corrosion prevention products.

These include both the Anti Corrosion Spray as well as the market leading Corrosion removal liquid.