The affected areas will have hard, brittle, white deposits, which can compromise the integrity of the aluminum for certain applications, causing leaks in aluminum storage tanks, for example. Lastly, situations that allow crevices and pits to contain a buildup of harmful chemicals may lead to localized corrosion in aluminum parts and equipment.
Under galvanic corrosion situations where aluminum is at risk, it will corrode at an accelerated rate instead of the other metal.įor this reason, aluminum anodes are commonly used as a cathodic protection measure for other metals, using the aluminum anode as a sacrificial element that breaks down over time to prevent corrosion on the other metal, often made of steel. This is because aluminum tends to be the less noble, or more reactive, metal in these situations. The acidity or basicity of the surrounding environment of aluminum will substantially affect on its corrosion resistance.Ī Pourbaix diagram of aluminum, which plots the zones of electrochemical equilibrium for aluminum depending on the pH level of the environment, shows how susceptible to corrosion it becomes when the pH levels become too acidic or too basic.Īluminum is also in particular danger when used in an environment where galvanic corrosion can occur, which is when two different metals are electrically connected. The conditions to which aluminum alloys are exposed can also heavily impact their corrosion resistance. The Impact of the Environment on Corrosion Resistance
#Will aluminium rust series#
In particular, alloys of the 2XXX series (alloyed with copper) and 7XXX series (alloyed with zinc and small amounts of magnesium) have much lower corrosion resistance when compared with pure aluminum. However, they also diminish aluminum’s natural corrosion resistance. These alloying elements can enhance the aluminum, for example, by increasing its strength, workability, wear resistance, or ductility.
Aluminum is often alloyed with other materials, such as magnesium, copper, silicon, and zinc, to attain specific properties. This natural protection of aluminum works slightly differently depending on the aluminum alloy in question. In a way, aluminum creates its own defense against corrosion by forming a layer of aluminum oxide on its surface. It serves as a shield preventing any further oxidation of the aluminum. However, unlike iron, the layer of oxide most commonly formed by aluminum is not flaky or overly porous.
In its pure form, aluminum also oxidizes when in contact with water or humid air, just like iron. How Does Corrosion Affect Aluminum and Its Alloys? These two categories of corrosion can be further subdivided into other forms of corrosion, which can be exacerbated or slowed by factors such as temperature, electrolyte chemistry, or even the presence of other metals.
General corrosion, which affects a large area more or less uniformly, and.There are many types of corrosion that fit into two categories: Technically, other forms of corrosive oxidation on metals such as copper and aluminum are not “rust.” The most widely known metal corrosion is rust, the orange, flaky oxidation film that forms on iron and alloys containing iron. This process results from an electrochemical reaction between one or more materials and an electrolyte.Īlthough it can affect other materials, corrosion is most commonly seen in metals. Consider Alloys, Environment, and Finishing CarefullyĬorrosion is the gradual destruction of materials when exposed to certain environmental conditions.Can You Enhance Aluminum’s Corrosion Resistance?.The Impact of the Environment on Corrosion Resistance.How Does Corrosion Affect Aluminum and Its Alloys?.
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