steel and aluminium

[Nick93]

Hi,

Should bolting a steel plate to an aluminium surface cause corrosion problems?

I recently had an ABS problem on a car and traced the fault to the gap between the sensor and the wheel rotor. The gap had increased due to corrosion build up.

The sensor is mounted onto a steel plate at the rear of the wheel hub. The wheel hub is made from aluminium and the corrcsion had built up between the two materials to such a degree, that it pushed the steel plate away from the hub; thus increasing ABS sensor gap.

Thanks

 

[Nick93]

Hi guys again,

Going back to my original problem layed out at the start, would GROUNDING the "wheel hub"/"steel backing plate" assembly to chassis potential disipate all electrical potential held within the different metals?

 

[CoryPad]

No, that won't fix your problem. As long as the dissimilar metals contact each other, and are connected with an electrolyte, then adding an electrical path to another part won't help. My message from 11 May 05 9:21 is really your best solution based on price and performance.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Nick93]

Thanks for the input Cory. Its been an interesting subject to research.

What profession are you in?

 

[CoryPad]

I work as a Materials Engineer for an automobile manufacturer. You can learn more about any user on this site by clicking on his/her handle.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Rob45]

patprimmer wrote,
"Water with the slightest salt content, or acid from dissolved gasses is an electrolyte"

Rain, for example.

Just a few years back, Ford ran a little science experiment by putting aluminum decklids on Lincolns. It was a short-lived experiment, as the steel hinges contacting the aluminum skin prompted the aluminum to corrode right through, usually in a year's time or sligthly more.

They've since done quite a bit of study of galvanic corrosion...

 

[Nick93]

Hi everyone,

Once again thaks for all the input. I'l echo a point i made earlier on in that this has been an interesting topic research.

If anyone is interested, see my final case study

http://WWW.HIBTECH.COM

then FERRARI 456 ABS part 2.