Video Transcript
In a certain process, a new layer is naturally created on the surface of a metal. This layer is less reactive and protects the metal from corrosion. What is the name of this process?
Typically, corrosion is thought of as a negative phenomenon since it weakens the
strength of metals. It can be defined as a process where a metal reacts with other substances to form
more stable compounds. Metals corrode from the outside inwards. First, the outer layers corrode by reacting with substances such as oxygen and
water. These corroded layers will often peel back, exposing the metal underneath that has
not corroded yet. These exposed areas now corrode and peel. And the process repeats until all of the metal has corroded.
As a solution to this problem, the surface of a metal can be reacted with another
substance or series of substances to create a thin layer of a metal compound that is
resistant to corrosion. This would prevent it from corroding and undergoing damage. This process occurs naturally for metals such as aluminum and chromium. These metals react readily with oxygen and water to form a protective barrier on
their surface. These protective barriers that are formed are compounds that stick to the metal and
do not peel, preventing corrosion.
For metals that this process does not occur naturally, we can treat the surface to
encourage the production of the protective barrier. This process that can occur naturally or by treatment to form a protective barrier on
the surface of a metal part is called passivation. Therefore, the name for this process where a new layer is naturally created on the
surface of a metal to protect the metal from corrosion is called passivation.
