Electrodeposition and Electrolcss Deposition of NiWP Alloys

摘要

Electrodeposition and electroless deposition of NiWP alloys from a solution containing NaH_2PO_2, Na_2WO_4, NiSO_4 and Na_3C_6H_5O_7 is investigated in this work. Electrodeposition at room temperature (22℃) leads to a production of NiP alloys with a composition (12%P and 88%Ni) practically independent on current density within the investigated range (20 to 100 mA/cm~2). At elevated temperatures the incorporation of W into deposit was observed. An increase in temperature from 22 ℃ to 80 ℃ leads to the increase in W content from 0 to 12 %. The efficiency of NiWP alloy deposition increases with an increase in temperatures. This observation is attributed by the simultaneous electroless deposition due to presence of hypophosphite, which acts as a reducing agent of Ni(Ⅱ) ions at temperatures above 60 ℃ in the system investigated.