Stoneridge Engineering Home |
Hello Ben, Is the intended application DC, low frequency AC, or a pulsed application? Also, what material(s) are you planning to use to make sliding contact to the rods? Finding the proper material combination will be critical since, at high current densities, contacts become unstable due to the interactions between magnetic repulsion forces and current constriction at the individual points of contact. This can leading to arcing and rapid deterioration of the contact area. The challenges of making high current sliding contacts have been worked by developers of high current homopolar generators or compulsators. Copper-graphite (fabricated via powder metallurgy) seems to be the material of choice for high current brushes. The potential rod materials you've researched are reasonable choices for high current contact applications. As you've found, they are all fabricated using powder metallurgy and they are not generally available in lengths greater than 8-12". There's also an inverse relationship between the electrical conductivity and wear resistance, and the effective melting temperature of the rod may still be limited to that of silver. If your application is mainly DC or long pulse duty, I'd consider using electrolytic silver square or hexagonal bar stock to provide the lowest resistance conductor. You could then silver solder or braze shorter lengths of thin WAg or WCAg rectangular bar stock to the flat outside surfaces of the silver rod to form tough, arc-resistant contact strips. The resulting composite structure should provide an optimal combination of wear resistance and low electrical resistance. Good luck and best regards, -- Bert --
: I need to conduct several tens to hundreds of kA though a thin sliding
: contact rod. I've yet to settle on a size because it will partly depend on
: the material. I don't like copper for fear it will begin to melt.
: It needs to be arc resistant, high melting point, and good conductivity.
: I would use elkonite (the WC Ag variety) but it doesn't come longer than
: 12" apparently. The other option I've come up with is Cu Zr but I've
: done little reasearch on this yet.
: What are other good materials for this application? they need to come in
: >3 ft lengths.
:
Message Thread
« Back to index | View thread »