Electrodeposition of Low Contraction Chromium Using High/Low Current Pulsing

摘要

The effects of high/low current pulse plating on the electrodeposition of lowcontraction (LC) chromium were evaluated and compared to direct current-electrodeposited LC chromium with respect to microstructure and mechanical properties. A systematic experiment was performed in which three high/low current densities, 200/100, 200/60, and 200/30 A/dm(exp 2), were tested. The high current density time was varied from 0.6 to 60 ms, while the low current density time was kept constant at 30 ms. A high/low condition of 200/100 A/dm(exp 2) for 0.6/30 ms resulted in the overall optimal microstructure and mechanical properties with a resulting hardness value of 900 KHN, a cathode current efficiency of 22.1 percent, and an ultimate tensile strength of 25.8 Ksi. The deposit at this condition was crack-free with a typical columnar microstructure of fine fibrous grains and a <211> preferred orientation.... Low contraction, High/low current, Pulse plating.