Summary for electropolishing zinc coating Discussion
Electropolishing zinc coating and copper coating specimens for EBSD is the central issue in this thread, with Abbas Hussain reporting that his Struers LectroPol5 trials on porous cold-sprayed coatings are causing surface melting or poor polishing. Ken Vlach says that for copper, phosphoric-acid electrolytes are commonly used, while zinc is typically polished with 25% KOH, and both are done at room temperature. He also notes that Struers should be able to supply parameters, and that the LectroPol5 brochure indicates a preprogrammed copper method; Struers also has an application note on zinc coatings, though it does not cover electropolishing. Abbas adds that KOH works poorly on his zinc coatings and ethanol-based electrolyte works on bulk zinc alloys but not on the coatings, so he is seeking practical guidance on electrolyte type, temperature, voltage, flow rate, and time. The thread does not give exact settings, only general starting points and a recommendation to consult Struers.
I am doing project work in international advance research center for powder metallurgy and new materials, Hyderabad. My project title is “electropolishing zinc coating and copper coating specimens for ebsd”, the machine is made by Struers LectroPol5. I tried with different parameters. coating porosity is high due to this surface is melting, am using ethanol based electrolyte. I want information about electropolishing, voltage, flow rates, time, etching time, voltage for zinc, copper coatings. What’s the temperatures of electrolyte for electropolishing (if important), any other information as needed. Thank you
Abbas Hussain
int’l advance research center
for powder metallurgy
and new materials
Hyderabad, India
2007
2007
A. Ebsd is what, maybe electron beam surface deposition? Was ebsd used in preparing the coatings, or will it be used after electropolishing?
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, 4th Edn., has a chapter on electropolishing. For copper, phosphoric acid electrolytes are used. For zinc, KOH (25%) is used. Both are done at room temperature. Struers should be able to provide parameters; a method for copper is preprogrammed into the ‘LectroPol5’ according to its brochure. They also have an application note on Metallographic preparation of zinc coatings — doesn’t mention electropolishing, though.
Ken Vlach [deceased]
– Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
I am doing project work in international advance research center for powder metallurgy and new materials, Hyderabad. My project title is “preparation of zinc coating and copper coatings using cold spray and electropolishing (Zn Cu coatings)for EBSD (electron back scattered diffraction) on FE-SEM Hitachi S-4300”. My project main key is comparing the results between manual polishing and electropolishing electron back scattered diffraction. The machine is made by Struers LectroPol5.
I tried with different parameters. Coating porosity is high, substrate is MS, for zinc KOH (25%) is used at room temperature — but this electrolyte is not effective on coatings i.e., coating is not polished, and ethanol-based electrolyte is giving good results on bulk zinc alloys and it’s not effective on zinc coatings . I want information about type of electrolytes, temperature, voltage, flow rates, time, etching time, voltage for zinc, coatings. Thank you,
Abbas Hussain [returning]
int’l advance research center
for powder metallurgy
and new materials
Hyderabad, India
2007
2007
How to mechanically polish cold spray zinc coated samples? It’s thickness is 150 to 50 µm;
hardness around 75 Vickers.
Collidal silica is detected on coated surface
Abbas Hussain [returning]
int’l advance research center for powder metallurgy and new materials — Hyderabad, India