Search for a material with electrical resistance and high hardness

[lgracio]

Please someone could help me search for a material with good properties of wear resistant or high hardness and simultaneously with electrical resistance features. This material is to be used as a tool disc to block and guide a fin strip plate and push it against tube where is to be welded with high frequency welding process, in that matter a reason to avoid electric current passing through the tool because it erodes the material regarding the effects of electrical fatigue.

The prevision of service conditions are:

Temperature = 40ºC up to 100ºC
Pressure = 40 Barg

I appreciate all your help on this. Thanks.

Luís Grácio
Mechanical Engineer (Engineering Solutions)
Portugal-Setúbal

 

[Ceramicguy]

If the ceramic is not near the welding heat, aluminum oxide is an excellent, low cost option. If the ceramic is immediately adjacent to the weld then a more thermal shock resistant material like silicon nitride can be used.

 

[tomwalz]

Ceramicguy pretty well nailed it.

I have seen machines for brazing and welding where they use a standard machining insert. Easy to buy, relatively inexpensive and easy to replace.

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[Ceramicguy]

Tom makes a good point. Bonus, the inserts are available in aluminum oxide ceramic or silicon nitride. The silicon nitride ones are probably more available and are usually specified for turning cast irons.

 

[Ceramicguy]

You can also use a sialon lathe tool insert. It is electrically insulating and wear resistant just like the aluminum oxide and the silicon nitride. It might be a little less expensive than the silicon nitride inserts.

Bruce

http://www.accuratus.com

 

[unclesyd]

Based on my experience I would start off with the best Sapphire and maybe later change to somethings else.
You haven't mentioned the configuration of your guides like vertical rods, parallel blades, doctor blades, rollers, etc.

If possible comeback with that information.

Here is the some general information on Sapphires.

http://www.photonic.saint-gobain.com/sapphire-materials.aspx