Manganese Alloy Electroplating
Hi, I would like to know if it is possible to electroplate any of the following alloys, NiMn, FeMn, PtMn, and if so where do I get the baths from? JimJames McGrath
- Cork, Ireland
There is not to much info in the literature on those alloys you want to plate. The one reference I have is Brenner's Electrodeposition of Alloys vol. 2 lists some of the electrolytes used to produce MnNi, MnCo and MnCu. These were mostly simple salt solutions of the metals, usually sulfate.
If you do not have access to this publication I could send you the formulas listed in this book.
- Rock Hill, South Carolina
NiMn, FeMn, are depositable from either a simple salt bath or from a complex salt bath at wide ranges of pH and temperature, preferably room temperature. They can be electroplated, or electrolessly plated from a sulfate or phosphate bath of one's formulation.
Bassey J. Udofot|
What are the concentrations and pH of the bath to deposit FeMn in the proportion around 50/50 (Fe50Mn50)? I have tried common sulfate solutions, as Mr. Udofot suggested, and the Fe composition is always much greater than that of Mn. Ex: Fe93Mn7.José Gomes Filho
- Rio de Janeiro, BR
Dear Readers and Mr. Gomes,
As I have already demonstrated, Fe and Mn intermediate composition in alloy films of Fe-Mn are depositable from a simple salt bath without the use of complexant or metalloids. The reason you have found electo-deposition of Fe more than the Mn is of great interest and and has been found to cause discrepancies in the published work of other Research Scientist as published in the Abner Brenner's text volume 1 and 2. It has been generally believed that in alloy films, the more noble metal deposits preferentially than the less noble metals. If the reverse occurred, it is often explained as anomalous reaction. In simultaneously depositing of Fe and Mn from a simple sulfate or chloride salt baths, the maximum at wt % Mn that codeposited with the Fe as ductile Fe-Mn alloy films was 13 wt%. As either the pH or temperature of the bath increases, the wt % Mn codepositing with the Fe decreases whilst the Fe continues to increase in the deposition. As the temperature of the bath reaches 80° C., Mn ceases to co-deposit and only the Fe deposits as a dark, coherent, hard, magnetic ferri-ferrous iron oxide film. Similarly from a simple salt bath at pH 11.5, room temperature, only Fe deposited as bright Fe oxide film, on a substrate. intermediate composition of Fe and Mn occurred from bath of pH 1 to 2 at room or near rooms temperature ranges. The key to depositing the intermediate composition is based from good knowledge of the two materials behavior from the aqueous solution environment and their diffusion rates. Electrodeposition of Fe-Mn alloys containing P and nitrate salt from bath at pH 1.5, 50 ° C., will deposit 50 at wt % Mn and 29 at wt% Fe and the rest P. Similarly, in Fe-Ni alloy electrodeposition, Fe being the less noble metal than Ni, deposits more than the Ni. Therefore, it is not the question of nobility or lack of it that determine the preferential deposition of a metal. It has to do with freedom with which metal looses its electron to deposit on a cathode. The ability of the ionized metal to overcome the influences of Oxygen and OH- ions across the diffusion layer,to deposited on a substrate that determines thermodynamically the at wt. % metal deposition in an alloy films from bath.
Bassey J. Udofot|
June 12, 2012
in electrodeposition of NiMn alloy sulfate single bath, what concentration of each element is needed to get 50% of Ni and Mn?
- Tebessa, Algeria
December 15, 2012
A. My use of Cyclic Voltammetry to study metal alloy deposition shows that, thermodynamically, Mn can co-deposit with Ni at a negative cathode potential of -1.18 electron volt, nearer that of Mn to form Ni-Mn alloy having a non-equilibrium at weight composition. As the depositing potential of the system became less negative, more Ni than Mn was found to deposit at a potential of -0.25 electrode volt. However, for kinetic reason, particularly because of their cathode potential difference and tenacious oxide stability on their surfaces, alloy co-deposition of intermediate composition of 50 % weight Mn with 50% weight Ni is not possible. The only method to co-deposit Mn and Ni from aqueous solution of simple salt is to add increased concentration of Phosphate in the Nickel-Mn salt bath. More P concentration in the bath, more Mn and Nickel close to 50 % at wt %, each would co-deposit as an alloy of Mn-Ni film. Alternatively, the two metals when dissolved and ionized to diffuse to deposit at the same speed, Ni will inhibit Mn and itself deposit preferentially a chosen target than Mn unless their accelerations to reach the intended target are controlled. Controlling their rate of acceleration to diffuse to their depositing target will ensure intermediate at weight composition of the Mn-Ni alloy films.
Bassey J. Udofot|
- Musgegon, Michigan USA