PROCESS MODELING OF A NOVEL PLASMA ENHANCED VAPOR DEPOSITIONCONCEPT USING STATISTICAL DESIGN OF EXPERIMENTS.

CADMIUM IS ELECTROPLATED IN CYANIDE BATHS IN 1166 FACILITIESACROSS THE U.S. DURING THE PAST TWO DECADES, CONSIDERABLE RESEARCH HAS BEEN CONDUCTED TO REDUCE TOXIC CHEMICAL DISCHARGE FROM CADMIUM ELECTROPLATING OPERATIONS. HOWEVER, ECONOMICAL ELIMINATION OF CADMIUM DISCHARGE OR SLUDGE HAS NOT BEEN REPORTED. TO ADDRESS THE ENVIRONMENTAL ISSUES RELATED TO CADMIUM ELECTROPLATING, A NOVEL PLASMA ENHANCED VAPOR DEPOSITION CONCEPT WAS DEVELOPED IN THE LABORATORY. IN ADDITION TO HIGH DEPOSITION RATES FOR CADMIUM AND ZINC (5 TO 10 MUM/MIN), THE FEASIBILITY OF IN-SITU CADMIUM RECLAIM IS DEMONSTRATED TO ELIMINATE TOXIC CHEMICAL DISCHARGE. IT IS ALSO FEASIBLE TO EXTEND THIS CONCEPT TO DEPOSIT OR RECLAIM ZINC-CADMIUM ALLOYS. HOWEVER, AN UNDERSTANDING OF THE EFFECT OF PROCESS VARIABLES ON THE DEPOSITION RATE AND PROPERTIES OF CADMIUM IS REQUIRED. A SYSTEMATIC RESEARCH USING STASTISTICAL EXPERIMENTAL DESIGN METHODS HAS BEEN PROPOSED IN THE PHASE I TO DEVELOPE THIS UNDERSTANDING. THEPROPOSED RESEARCH COULD LEAD TO AN ENVIRONMENTALLY ACCEPTABLE CADMIUM VAPOR PLATING PROCESS (DRY PLATING) AS ANALTERNATIVE TO CYANIDE ELECTROPLATING.