Indian Space Research Organisation has developed a micro arc oxidation process for magnesium alloys which will find wide commercial and industrial applications.
Mirco Arc Oxidation (MAO) coatings find application in the various engineering industry for components, which require corrosion resistant and very high wear resistant surface such as pistons, cylinders, and hydraulic gear and for variety of components in aerospace industry. These coatings also improve the tribological properties of the components. These coating are also used in various components of automobile industries to improve their durability, corrosion resistance and heat radiation characteristics. It also offers high heat resistance. Components coated with thick MAO film can withstand unusually high temperature for a short duration.
Magnesium and its alloys are rapidly becoming the material of choice across a wide cross section of industries such as aerospace, automotive, consumer electronics, defence and biomaterials. The traditional problems of magnesium are its susceptibility to corrosion and poor wear/scratch resistance.
MAO also known as Plasma Electrolytic Oxidation (PEO) or Spark anodization is relatively a new surface treatment technique, which uses a high voltage, high current process to obtain a hard, corrosion resistant oxide coating on the surface of metal surface. This produces a hard, dense ceramic like coating formed on magnesium alloy surface have a superior corrosion control properties comparable to stainless steel.
In addition, the coating offers better thermo-optical properties, abrasion/ wear resistant properties.
Salient features
• High voltage, high current process, which is carried out at +25o C with an AC power supply
• Hard ceramic like coating with superior corrosion resistant and abrasion / wear resistant properties
• Green Process and no pre-cleaning of component needed
• Tailor-able coating thickness and hardness
Also, the high insulation value of coating makes it useful in developing a dielectric layer with a breakdown strength of about 25 -30 V/micron thick coating. This coating is also used in Mobile phones and laptop casing.
For further details,please contact please contact please contact:
Technology Transfer & Industrial Coordination Division
Vikram Sarabhai Space Centre Indian Space Research Organisation
Thiruvananthapuram – 695 022
E-MAIL: u_sreerekha@vssc.gov.in
