The Effect of Silver Coating on the Corrosion Behaviour of Ag-Doped Magnesium Alloy NZ30K in Ringer–Locke Solution

The paper investigates the effect of silver coating on the corrosion behaviour of magnesium alloy NZ30K alloyed with 0.09 wt.% Ag in Ringer-Locke solution.Samples of the alloy under study are plated with a silver layer of 200-300 nm and 500 nm thickness using the DC-magnetron sputtering system equipped with a circular silver source and target (of 50 mm in diameter) in a gas discharge.An unbalanced magnetron in a 600 mA DC mode at a voltage of 400 V is used.The silver coating at a constant magnetron power of 240 W and a bias voltage of 100 V is applied.The deposition time of a silver layer of 200-300 nm is of 5 minutes, and for 500 nm, is of 15 minutes.As found, the steady-state value of the corrosion potential Ecor for the samples of the studied alloy clad with a silver layer of 200-300 nm is formed during 2060 s from -1.418 up to -1.4449 V, and with 500 nm layer, during 1880 s from -1.433 up to -1.465 V.As recorded, the steady-state value of Ecor for both samples is established in two stages.