Optimization and kinetics of electroless Ni–P–B plating of quartz optical fiber

The preparation of Ni–P–B coatings on surface of quartz optical fibers was carried out using electroless plating method. The effects of the concentrations of nickel chloride, sodium hypophosphite, potassium borohydride, ethylenediamine, cadmium sulfate and temperature on the quality of Ni–P–B coatings were investigated by orthogonal experiment and their optimal values were determined to be: 0.1 mol L−1, 0.094 mol L−1, 0.185 mol L−1, 0.36 mol L−1, 5.68 × 10−4 mol L−1 and 90 °C, respectively. The effect of coarsening time of the naked fiber on the quality of Ni–P–B coatings was also researched and the optimal coarsening time was determined to be 15 min. Stereomicroscope, Scanning Electron Microscope and X-ray diffractometer were used to characterize the apparentness, morphology and structure of the prepared Ni–P–B coatings. Inductively Coupled Plasma-Atomic Emission Spectroscopy, Thermal Shock Method and Gravimetric Analysis Method were employed to analyze the composition, force of adhesion and solderability of the coatings, respectively. The results showed that a Ni–P–B coating with low surface roughness, good strength of adhesion, low resistivity and good solderability was successfully prepared. The kinetic models (Ni–P–B deposition rate equations) of the process were established as v=7.95×10-6cA0.830cB0.428cC-0.288cD-0.645cE0..02exp26788(T-298)298RT;v=1.03×10-7cA0.830cB0.428cC-0.288cD-0.645cE-0.614exp26788(T-298)298RT. The theoretical values calculated by the models were proved to be basically consistent with the practical measurements through experimental verification.