"jim rozen" wrote in message
...
In article , Harold and Susan Vordos says...

Mechanical as regards strength, hardness, and machineability.

Use aluminum,
But probably horrible in the way of contact value, however.

Umm, Harold, that wasn't one of the properties he listed.

Chuckle!

Just thought the information might be useful. I can see it all now. An
aluminum oxide grinding wheel used as a contact. Somehow, it sort of
loses something along the way. On the positive side, it doesn't arc
much! g

Aluminum
enjoys forming aluminum oxide rapidly---which is not known for its good
electrical properties.

Heavy duty silver contacts are made from tungsten powder and
silver------which yield the best of all worlds. Don't have a clue how
they'd machine, but I can't help but believe they'd be tough on tools.

They also use to be made from sintered silver, Wo, and Cd. I
knew a group at GTE labs that were trying to eliminate the Cd
from those.

Jim

I encountered the cad filled ones occasionally. It blended so well with the
silver that you weren't aware of its presence, yet there was a loss in
weight when the overall mass was processed. Had to be Cd. I can't help
but think that they were in better quality house switches and other light
duty devices. It's been too long to remember.

Harold