Horn contact material question

[StealthyOne]

HI
First, I'm new here. I have a design problem I am trying to come to resolution on related to a 12v electric horn contact (auto).
I'm creating a custom design that consists of an existing (.025" brass I believe) contact "ring". The design problem is what conductive material to interface with the brass to create electrical continuity...that is, to the horn button.
i have narrowed it down to (2) solutions...keep in mind, both solutions consist of a gliding "spring" contact that would "ride" on the surface of the brass ring. My issue - what material is best?
material #1 = a .012" thick phosphor bronze c510 (nickel plated)
material #2 = a .025"-.032" 260 brass (1/2 hard)

Either would be applying about the same spring force on the .025" brass ring.

Which would work best, and why? I have my own thoughts, but signed up here to find out what the experts thought.
Thanks in advance for any input! Its appreciated.

 

[EdStainless]

One problem with sliding contacts is surface corrosion. If the switch goes unused for some time a thin layer of corrosion products will build up on the surface. So which combination is best at resisting corrosion, or perhaps wipes better when actuated?
The Ni is corrosion resistant, but also quite hard, it will wear into the brass over time, but it might provide better contact.

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P.E. Metallurgy, Plymouth Tube

 

[StealthyOne]

Not sure my original explanation was clear enough...
The brass ring is almost always in motion (think of driving a car and how much you turn the wheel, as the ring is literally attached).
I do expect wear, but which combo will wear best is the question.

I agree the thinner ni coated 510 will provide better contact (providing it doesn't wear through) as it is a spring temper.
While the brass will never quite have that spring property as it's half hard, but may wear better (as a system) because both the ring and the contact are same material and thickness...I think some cycle testing may be in order

 

[IRstuff]

Why wouldn't you use an existing horn contactor?

TTFN
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[StealthyOne]

There is no existing horn connector for the application - hence the custom design.

 

[IRstuff]

You are supposedly using an existing contact ring, which suggests that there is an existing contactor that was originally intended to be used with the ring. Moreover, it seems to me that you could buy an existing contactor for some other contact ring and adapt it.

Why design something from scratch? If nothing else, the existing contactors for other products have the material compositions that were already deemed to be acceptable for this application. Why would you try to pick something different?

TTFN
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Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

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[StealthyOne]

Not quite that simple...I'll explain;
While the manufacturer supplies a ring, they do not supply a specific contact for my application, or any application that I'm aware of. They do manufacture a generic plunger style contact, but it will not work in my application, which is why I am designing one.