Topic: Duplex chrome
I have a customer requesting duplex chrome. We are a hard chrome plaating facility only. I have a general idea on what the concept is but what is the actual performed procedure?
Re: Duplex chrome
It is a layer of copper, nickel and then chrome.
Jim
Re: Duplex chrome
Jim is right (of course), but if you are looking to do a duplex chrome for say like a "Chrysler" or some other "Duplex" spec - there could be much more too it. Like for example it will tell you the thickness range of deposits, ie) xx mils of dull Ni, and xx mils of brite Ni, and xx mils of Cr. Could also specify polishing in between steps.
I'm sure somebody will jump on this thread soon and break it down for you.
If you are only a hard Cr shop it could be quite costly to put in the nickel tanks (and buffing, etc.) so if you want to entertain bidding the job - think capital equipment....
Re: Duplex chrome
I agree with Jim and Paul. Duplex is an industry term meaning 2-layers, typically copper-nickel(-chrome) or dull nickel-bright nickel(-chrome). You can even go further (triple nickel, quad-nickel, copper-quad-nickel, etc). If you are only doing hard chrome, you will definitely need to install the nickel plating tanks, just as Paul has said.
-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC
Re: Duplex chrome
Jason,
I agree with Paul and Dustin 100% and that is why i kept my response short. To set set up what you need to complete this job you are looking at what would require much more space and financial input. I know that the hard chrome buisness has been taking a hit as of late and you are probably looking to find ways to increase profits (as we all are). There is also the increase in waste treatment, nickel and chrome can be traeted together but you might have to expand it also. So is it feesable for you? I don't know but only you can answer that. We are just tring to offer some insight.
Jim
Re: Duplex chrome
Thanks for all your replies. The end use is hydraulic cylindres. I believe in a high humidity enviro. In the past we use to deposit .001" to .002" hard chrome per side on these new cyl. But i guess through idle time, the humidity got through the micro cracking of the chrome and is attacking the base material and then failure to the deposit. So i guess a nickel then chrome deposit would prevent this??
Re: Duplex chrome
I have encountered old worn hydraulic cylinders having an underlayer of nickel. These were working on ships and thus were subject to more severe corrosion attack by the marine environment. I also recall the same with landing gear shafts of the CL 215 Canadair aircrafts.
But when I read about "duplex chrome" my mind goes to something I have read somewhere in the past. You first hard chrome plate the part in high temperature (can't exactly remember, I guess above 60C degrees), which gives you a soft non-cracked "hard chrome" coating, better resistant to corrosion and then you go on plating thicker hard chrome as usual onto this.
Have not tried and don't know if it works, of course it cannot be the same with Ni/Cr, but this way you do not need extra tanks and processes.
Last edited by Chrisig (09/14/2009 - 06:52 AM)
Re: Duplex chrome
I agree with what you said 100%. But I guess what JASON need duplex chrome means two layer of chrome,one regular chrome and the other microcracked
