Electroless alloy coatings having metallic particles dispersed therethrough

Abstract

Abstract THERE ARE DISCLOSED HEREIN PROCESSES FOR ELECTROLESS METALLIZIN WORKPIECE TO PROVIDE THEREON AN ELECTROLESS PLATING METAL COATING INCORPORATING THEREIN METALLIC PARTICLES, WORKPIECES PRODUCED BY SUCH PROCESSES AND PLATING BATHS WHICH ARE USEFUL IN THE PRACTICE OF SUCH PROCESES AND FOR PRODUCING SUCH WORKPIECES. THESE PROCESSES GENERALLY COMPRISE CONTACTING THE WORKPIECES WITH AN ELECTROLESS METALLIZING BATH CONSISTING OF AN AQUEOUS SOLUTION OF AN ELECTROLESS METAL PLATING SALT AND A CHEMICAL REDUCING AGENT THEREFOR AND A QUANTITY OF METALLIC PARTICLES, WHEREIN SAID PARTICLES ARE ESSENTIALLY INSOLUBLE IN SAID BATH AND INERT AND NON-CATALYTIC AND NON-POISONOUS WITH RESPECT THERETO AND NON-DISPLACING WITH RESPECT TO THE ELECTROLESS PLATING METAL IONS IN SAID BATH, THE PARTICLES BEING PRESENT IN SAID BATH IN AN AMOUNT BY WEIGHT NO GREATER THAN ABOUT TEN TIMES THE WEIGHT OF THE ELECTROLESS PLATING METAL IN SAID BATH EXPRESSED AS FREE METAL, AND MAINTAINING THE PARTICLES IN SUSPENSION THROUGHOUT THE BATH DURING THE METALLIZING OF THE WORKPIECE; THE METALLIZING BATH MAY CONTAIN NICKEL IONS OR COBALT IONS OR MIXTURES THEREOF AS A SOURCE OF METAL AND MAY CONTAIN HYPOPHOSPHITE ANION OR AN ALKYLBORAZANE OR A BOROHYDRIDE AS THE REDUCING AGENT, OR MAY CONTAIN COPPER IONS AS A SOURCE OF METAL WITH FORMALDEHYDE AS THE REDUCING AGENT; THE METALLIC PARTICLES ARE SELECTED FROM CHROMIUM, MOLYBDENUM, TUNGSTEN, BORON, TITANIUM, VANADIUM, ZIRCONIUM, NIOBIUM, TANTALUM AND ALLOYS THEREOF; THE METALLIC PARTICLES HAVE DIMENSIONS IN THE RANGE FROM ABOUT 0.1 MICRON TO 50 MICRONS; THESE METALLIC PARTICLES MAY BE MAINTAINED IN SUSPENSION IN THE BATH BY MECHANICAL AGITAGION, BY PASSING THE BATH INCLUDING THE PARTICLES OVER THE WORKPIECE, BY PASSING STREAMS OF MINUTE BUBBLES OF GAS THROUGH THE BATH, BY AGITATION AND MOVEMENT OF THE WORKPIECE WITHIN THE BATH, OR BY SLOWLY ROTATING THE WORKPIECE IN CONJUNCTION WITH THE RAPID CIRCULATION OF THE BATH; ADDITIONALLY, THE ELECTROLESS PLATING METAL COATING HAVING THE METALLIC PARTICLES INCORPORATED THEREIN MAY BE HEAT-TREATED BY HEATING TO A TEMPERATURE IN THE RANGE FROM ABOUT 200* C. TO ABOUT 1,300*C. FOR AT LEAST ONE-QUARTER HOUR TO BOND SAID ELECTROLESS METAL COATING AND SAID METALLIC PARTICLES AT THE INTERFACES THEREOF.

Inventors

• 👤 K Parker

Bibliographic Details