Chromium plating is a well-known method of case hardening. For good appearance and lower coefficient of friction, the subsequent mechanical polishing is often implemented after chromium plating. For wear resistance and corrosion resistance of magnesium or aluminum alloys, the eco-friendly micro-arc plasma oxidation (MAPO) is far superior to chromium plating. The comparison between micro-arc plasma oxidation and chromium plating is listed as following:
The comparison between micro-arc plasma oxidation and chromium plating
Item |
MAPO |
Chromium plating |
Conformal converage |
Good |
Good |
Hardness |
High(~Hv1500) |
High(Hv800~1000) |
Adhesion |
Metallurgical interface, extremely excellent |
Mechanical interlock, good |
Conductivity |
Insulator with high dielectric strength |
Electric conductor |
Corrosion resistance |
Excellent |
Good |
Flexibility |
Excellent |
Fair |
Alloy choice |
Only vale metals(eg. Mg, Al, Ti alloys) |
Most of structural alloys |
Environment |
Eco-friendly |
Toxic |