Method of electrodepositing duplex microcrack chromium

Claim 1

A PROCESS FOR ELECTRODEPOSITING BRIGHT DECORATIVE CORROSION RESISTANT DUPLEX CHROMIUM ON A BASIS METAL COMPRISING (1) ELECTRODEPOSITING A FIRST LAYER OF CHROMIUM TO A THICKNESS OF AT LEAST 0.25 MICRON FROM A SOLUTION HAVING A CRO3 CONCENTRATION BETWEEN 150 G./1. TO 525 G./1., AND CONTAINING SULFATE AND FLUORIDE-CONTAINING CATALST IONS IN AN AMOUNT SUCH THAT THE RATIO OF CRO3 TO THAT OF THE CATALYST IONS IS BETWEEN 110:1 AND 175:1 WITH THE SULFATE IONS BEING BETWEEN 20% TO 85% OF TOTAL CATALYST IONS, AT A TEMPERATURE BETWEEN 32* C. AND 60*C.; AND THEN (2) ELECTRODEPOSITING ON THE FIRST LAYER OF CHROMIUM A LAYER OF CRACKED CHROMIUM HAVING AT LEAST 10 CRACKS PER CM. TO A THICKNESS OF AT LEAST .5 MICRON FROM A SOLUTION HAVING A CRO3 CONCENTRATION BETWEEN 150 G./1. TO 450 G./1., AND CONTAINING SULFATE AND FLUORIDE-CONTAINING CATALYST IONS IN AN AMOUNT SUCH THAT THE RATIO OF CRO3 TO THAT OF THE CATALYST IONS IS BETWEEN 50:1 AND 100:1 WITH THE SULFATE IONS BEING BETWEEN 20% TO 85% OF THE TOTAL CATALYST IONS, AT A TEMPERATURE BETWEEN 32*C. AND 60*C.; TO YIELD A DUPLEX CHROMIUM DEPOSIT HAVING A TOTAL THICKNESS OF AT LEAST 1 MICRON AND LESS THAN ABOUT 5 MICRONS.