The paper "Aircraft Corrosion" is an outstanding example of a literature review on physics. Corrosion is the electrochemical or chemical attack on a metal that ultimately leads to its deterioration. The resulting damage can occur on the surface as well as internally. The result of the deterioration is weakened structures, damaged parts, and change on the smooth surfaces. Crack nucleation is affected by different environmental, absence or presence of clad material, and loading conditions. Findings by SRI International (1999) suggest that crack nucleation is normally slower in bare material than in clad material.
In bare material, crack nucleated at constituent particles, whereas it nucleated at crystallographic pit colonies, in clad material. Fatigue on the metal occurs because of the load spectrum and varying operating conditions. Under the controlled lab conditions, changing the environment from a vacuum (10-6 torr) to lab air resulted to an accelerated rate of crack growth rate. According to SRI International, a localized type of corrosion is known as pitting. It results in cavities on the affected material. In addition, pits are a source of crack development.
Elongated pits occurring as a result of constituent particle erosion often leads to nucleated fatigue cracks. Alclad is a material formed by metallurgically bonding high-strength aluminum alloy with a high purity aluminum. The latter forms a surface layer over the alloy core. Alclad exhibits a longer fatigue life than the base material in both arsenated and salt water, by a factor of two. Aircraft skin is made from aluminum 2024. Its major alloy is copper. The copper gives it strength, but it reduces the aircraft's skin’ s resistance to corrosion. A clad layer is added because of its high resistance to corrosion as illustrated previously.