The Effects of Pulse Plating on Low Contraction Chromium Electrodeposits
ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
Pagination or Media Count:
The pulse plating of low concentration LC chromium using low pulse frequencies less than 50 Hz and high pulse frequencies greater than 90 Hz was evaluated and compared to direct current dc-plated LC chromium with respect to microstructure and mechanical properties. Low frequency pulse plating significantly increases the hardness and cathode current efficiency CCE over dc-plated LC electrodeposits but does not reduce deposit stress. Hardness values in excess of 1175 KHN 50 g load can be obtained with pulsing frequencies less than 26 Hz and duty cycles percent on-time less than 21 percent. CCE in excess of 22 percent can be obtained when pulsing frequencies are less than 12 Hz and duty cycles are less than 33 percent. This corresponds to a 54 percent increase in hardness and a 100 percent increase in CCE compared to dc-plated LC chromium.
- Metallurgy and Metallography