Corrosion refers to the degradation of metals due to a chemical reaction. The most important reactions to understand that cause corrosion are oxidation and reduction, and the critical substrates in these reactions are anodes and cathodes. When it comes to metals, oxidation is when oxygen from the atmosphere or water donates electrons to the metal it encounters. The site at which this donation occurs is called an anode. After oxidation occurs, the electrons flow to another location on the surface of the metal called a cathode. At the cathode, these electrons are finally donated to oxygen molecules in water droplets. This reaction is called reduction.
The oxidation step in this process results in the formation of an oxide. Iron, for example, is one of the most commonly used metals in the industry, and is also one of the metals most prone to corrosion. So when we see rust on a bike that has been sitting outside, we are witnessing the conversion of iron to iron oxide. The basic chemical equation for this is Fe (Iron) + O2 (Oxygen) -> Fe2O4 (Iron II Oxide). Looking at this equation, we can appreciate how a small chemical change can drastically alter a metal's physical properties. Corrosion makes metals weaker, more susceptible to holes, and can interfere with two parts' ability to slide past one another. Modern aircraft are primarily composed of aluminum, steel, titanium, and other composites. All these metals can corrode to a varying degree, and that process can be accelerated by harsh environmental conditions contributed by salt, moisture, and extreme temperatures. The annual cost of corrosion maintenance for aircraft across the industry is $1,000,000,000, and the risks don't end there. Failures caused by corrosion can put passenger lives at risk, and the downtime due to maintenance compromises operational readiness for military aircraft. As materials technology has evolved, engineers have made strides in making metals corrosion resistant.
Aircraft engineers employ several modalities to make metals corrosion-resistant. Painting, corrosion-resistant alloys, and corrosion inhibitors are all used as preventative measures. The paint that aircraft designers use works as a protective coating by forming a layer between the exposed metal and the ambient oxygen, salt, and moisture in the atmosphere. Alloys are made by combining two or more metals or nonmetals, and feature high strength and corrosion-resistance. These alloys are used to bolster the aluminum structures on an aircraft and delay the onset of corrosion. Finally, corrosion inhibitors, also known as anode corrosion preventatives, are chemical compounds that discourage corrosion by decreasing the rate at which agents like oxygen come into contact with metal. These inhibitors can come in liquid or foam, and work by forming a protective layer, or may alter corrosives like oxygen by turning it into water.
There are certain areas of aircraft that corrosion is more likely to form, thus requiring more frequent inspection and maintenance. The most obvious and easily inspectable corrosion-prone surface is the external part of the aircraft. It is crucial to look for cracks in paint and rust at more exposed areas like drilled pieces and rivets. Even with modern and improving battery design, sulfuric acid can leak and cause catastrophic corrosion and failure. Landing gear and wheel wells are exposed to the elements with every flight and can quickly accumulate water and dirt, which can precede corrosion. Since bilge areas collect water and hydraulic fluid as their routine function, it is evident that this portion of the aircraft should be regularly checked. In addition to inspection, regular preventative maintenance such as cleaning and lubrication can protect against costly mishaps.
Whether you are looking for anti-corrosive or replacement parts, ASAP Part Services is here to help you get back up and running. Offering the largest selection of parts for civilian and military aircraft on a single platform, ASAP Part Services can help you procure reliable and FAA-certified parts. You can browse our database or search for parts by number, manufacturer, NSN, type, or cage code. Our sales team is always available to help you navigate your needs and meet your demands. For a quote, contact us at +1-702-919-1616 or email us at firstname.lastname@example.org.
Remember Us the Next Time You’re Looking for NSN Parts. We Can Get You Some of the Quickest and Most Competitive Quotes In the Industry.
Request for Quote