I am trying to coat zirconia with electroless nickel, however, it would appear that the oxide surface is not active to the plating system. I am currently using a high phosphorous 10-13% system which does a beautiful job on most metals and some non-oxide ceramics. From what I have read it would appear that most electroless nickel systems for ceramic plating are ultra low phosphorous, but, the difference in the coating mechanism for metals vs. ceramics evades me. I would imagine a pre-treatment may be needed or a specialized plating system, but time is against me on this project. I appreciate any suggestions that may help.