Cast Copper 1-3% Chrome alloy

[clivelaurence]

Appararantly this alloy is difficult to cast without introducing defects. I suppose these would be gas or shrinkage or possibly dross defects. Has anybody got any experience in casting this alloy and have any tips as to how a good casting can be produced?

Thank you

Clive Jones

 

[Salvatio]

what type of casting method are you using? Sand casting?
maybe relocate the vent holes and degassing/deoxidizing may help to reduce the porousity or blow holes...

Relocating/redesign the risers or adding hot pads may also work for shrinkage...

What are you trying to cast anyway?

all the best to you..

 

[clivelaurence]

Thanks Salvitio

The castings are to be sand cast (with a large CO2 core). The product is a pressure ring cast in green sand (currently AB1 Al Bronze). It weights about 180kgs and is water cooled, it is used to push copper contact shoes on to a carbon electrode in a chrome smelter. Therefore it has to be pressure tight, conduct the furnace heat away and be mechanically strong enough to support a reasonable force.

Regards

Clive

 

[arunmrao]

Contact representative of Foseco for for any assistance. They have a range of products to produce a sound casting. Degassing practice, grain refinement are the important areas.Also purge the liquid metal with Argon or Nitrogen before pouring the metal. Use chills in heavy sections and insulating sleeves for feeders.If you can make the mold too in CO2 sand. Less of moisture related problems for you.

If you have any more concerns please feel free to ask.