Search results
Results from the WOW.Com Content Network
Anodic protection (AP) otherwise referred to as Anodic Control is a technique to control the corrosion of a metal surface by making it the anode of an electrochemical cell and controlling the electrode potential in a zone where the metal is passive.
Aluminum sacrificial anodes (light colored rectangular bars) mounted on a steel jacket structure. Zinc sacrificial anode (rounded object) screwed to the underside of the hull of a small boat. Cathodic protection (CP; / k æ ˈ θ ɒ d ɪ k / ⓘ) is a technique used to control the corrosion of a metal surface by making it the cathode of an ...
A galvanic anode, or sacrificial anode, is the main component of a galvanic cathodic protection system used to protect buried or submerged metal structures from corrosion. They are made from a metal alloy with a more "active" voltage (more negative reduction potential / more positive oxidation potential ) than the metal of the structure.
Certain metals, such as zinc, may become embrittled from the hydrogen gas which is evolved at the cathode. The anodic process avoids this effect since oxygen is being generated at the anode. The major advantages that are normally touted for the cathodic processes are: Higher levels of corrosion protection are possible.
Each process provides corrosion resistance, with anodizing offering a significant advantage when it comes to ruggedness or physical wear resistance. The reason for combining the processes can vary, however, the significant difference between anodizing and chromate conversion coating is the electrical conductivity of the films produced.
When the anode is made of the metal that is intended for coating onto the cathode, the opposite reaction may occur at the anode, turning it into dissolved cations. For example, copper would be oxidized at the anode to Cu 2+ by losing two electrons. In this case, the rate at which the anode is dissolved will equal the rate at which the cathode ...
Corrosion prevention measures, including Cathodic protection, designing to prevent corrosion and coating of structures fall within the regime of corrosion engineering. However, corrosion science and engineering go hand-in-hand and they cannot be separated: it is a permanent marriage to produce new and better methods of protection from time to time.
Electrochemical machining, as a technological method, originated from the process of electrolytic polishing offered already in 1911 by a Russian chemist E. Shpitalsky. [3] As far back as 1929, an experimental ECM process was developed by W.Gussef, although it was 1959 before a commercial process was established by the Anocut Engineering Company.