Problem with Ni plated Al. 6061

[bpss]

I have a small part (bushing) which is made up of 6061 Aluminum & bright Ni plated. I have seen severe corrosion of the material over time in marine environments. Can someone pl. suggest a cheap solution for the problem... short of replacing the Al. with exotic (& costlier materials).
Thank you for your help in advance.

 

[freewilly]

Give me so more info on the part and its use I have a few idea which might work. How much is the protection costing at the moments

 

[bpss]

The part is 1 in dia. x 0.5in long plug to seal an enclosure after assembly. The seal assembly involves pressing it into the enclosure, a seal is maintained using an o-ring along the dia. of the plug in question. Hope that this help. Thank-you for your help.

 

[freewilly]

I take it that its the exteria of the plug that is corroding? what is the require life span of the part? is there any temperature or pressure issues? what is the wear on the plug

 

[bpss]

Yes it is the exterior of the part. The life of the part to be at least that of powder (polyester) coated aluminum exposed to the same environment. Temp. min. 150 deg C & no pressure concerns. Min./no abrasives in the corrosive atmosphere.

 

[freewilly]

OK you could try Electoless nickel plate to 25 microns, then zinc nickel plate a further 25 microns and finish with full chromate passivate (gold is easyier to apply to the plating and looks great). This should give you a 25 year life. The chromate passivate will also give you a key is you want to apply a varnise or paint.

Or you could try Hot Thermal Zn or Al spray to BS EN 22063 150 micron, but you might want to seal it with varnise or paint depending on how the plug is fitted. I havn't used this on such a small part, but it will give a 25 year life.