Ads
related to: magnesium anode rod home depothomedepot.com has been visited by 1M+ users in the past month
Search results
Results From The WOW.Com Content Network
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.
Over time the galvanic anode continues to corrode, consuming the anode material until eventually it must be replaced. Galvanic or sacrificial anodes are made in various shapes and sizes using alloys of zinc, magnesium, and aluminum. ASTM International publishes standards on the composition and manufacturing of galvanic anodes. [10] [11] [12]
The magnesium–air battery is a primary cell, but has the potential to be 'refuelable' by replacement of the anode and electrolyte. Some primary magnesium batteries find use as land-based backup systems as well as undersea power sources, using seawater as the electrolyte. [5] The Mark 44 torpedo uses a water-activated magnesium battery.
Sacrificial metals are widely used to prevent other metals from corroding: for example in galvanised steel. [3] Many steel objects are coated with a layer of zinc, which is more electronegative than iron, and thus oxidises in preference to the iron, preventing the iron from rusting. [4]
Magnesium is anodized primarily as a primer for paint. A thin (5 μm) film is sufficient for this. [17] Thicker coatings of 25 μm and up can provide mild corrosion resistance when sealed with oil, wax, or sodium silicate. [17] Standards for magnesium anodizing are given in AMS 2466, AMS 2478, AMS 2479, and ASTM B893.
The terms anode and cathode are not defined by the voltage polarity of electrodes, but are usually defined by the direction of current through the electrode. An anode usually is the electrode of a device through which conventional current (positive charge) flows into the device from an external circuit, while a cathode usually is the electrode through which conventional current flows out of ...