Electroless nickel coating

Electroless nickel coatings, usually alloyed with phosphorus or boron, combine corrosion and wear protection with high dimensional stability. Heat treatment can increase the hardness of the hardness of the coating by precipitating Ni3P. The corrosion resistance of the coating increases with increasing P content.  In the example here, approx. 15 wt% P (25 at%) is contained. In places circular growth defects occur.