THERMAL EFFECTS OF A LASER-BEAM ON THE ELECTRODEPOSITION OF NI-P ALLOYS

The paper deals with the effects of an incident laser beam on electrod eposition of Ni-P alloys from dilute acetate solutions. The kinetics o f separate reductions of Ni2+ and H2PO2- species were first investigat ed by linear sweep voltammetry, varying the hypophosphite concentratio n and the solution temperature: comparison of the kinetically limited current densities of the two reductions suggested that increasing temp erature might reduce the significance of P codeposition. This tendency was confirmed by deposition runs carried out at controlled current. D eposition performance was discussed in terms of faradaic yield and dep osit properties, namely P content together with the aspect and the str ucture of the alloys. Use of a continuous or pulsed laser beam was sho wn to reduce the P content in the deposit at high current densities; i n some cases, amorphous structures were replaced by more crystalline f orms with assistance of a laser beam.