Try to proceed with electroless plating method. This method has the advantage to offer good adherence even on non-conducting substrate. Below, I suggest a bath formulation for electroless nickel plating:
Nickel sulfate: 80 g/L
Sodium hypophosphite: 24 g/L
Sodium acetate: 12 g/L
Boric acid: 8 g/L
Ammonium chloride: 6 g/L
It is known that the microstructure and mechanical
properties of a plated thin film depend upon the plating
conditions such as temperature, concentration and current
density. Surprisingly, little effort has been made to
clarify the relationship between processing conditions and
mechanical properties of plated thin metal films, particularly
of plated Ni.