Abstract:
In order to realize palladium free electroless nickel plating on the surface of the ceramic matrix, the mixed solution of 10g/L NiSO
4·6H
2O and 45g/L NaH
2PO
2 was used as activation solution and was coated on the surface of the matrix. The substrate was activated by laser scanning, and then electroless nickel was carried out. The effect of laser power, spot diameter and scanning rate on coating coverage was studied. The microstructure of coarsening, activation and plating was observed by a scanning electron microscope. The composition analysis of the substrate surface after activation and plating was analyzed. The adhesion, electrical conductivity and solderability of the coating were detected. The results show that, when laser power is 3W, the diameter of the spot is 2mm and scanning rate is 5mm/s, a layer of Ni particles with an average diameter of 0.1μm is generated on the substrate surface. The coating coverage is 100%. Micro surface of the coating is smooth and dense and the diameter of the cell is above 10μm. Mass fraction of P in plating layer is 0.0771, with good wear resistance and corrosion resistance for the amorphous structure. The coating has strong adhesion and good weldability. It is good conductor with the resistivity of 7.67×10
-5Ω·cm. With low cost and pollution-free, the process can realize local electroless nickel plating on the surface of ceramic matrix. By controlling the motion of laser, all kinds of fine graphics can be deposited on the surface of the matrix. The process has a certain practical value.