decrease casting cycle time (copper mold)?

[IHaveNoSpaceBar]

Adjusting to the right temps seems to consume most of our aluminum casting cycle time. The mold must be cooled first after the next part...down to 250c(from 650c).we use an air hose and have tried water.

I have heard about copper molds and the fact that they can reduce cycle times by 20-30%. Does anyone here use copper molds? Do they actually justify the higher price?

 

[arunmrao]

Have you tried water cooled molds,i.e have water jackets around the CI molds to cool them faster. Copper with today's prices will certainly be a no no. Also life of copper molds will not be as much as that of steel or CI.

 

[tripleZ]

We use the water jacket concept in our powder metal dies. It works well, but at the temperatures you're talking about, I'd recommend a decent sized holding tank with a chiller to cut down your water temp (assuming a re-circulating system...city water where I am isn't cheap). But then, I used to have a customer who pumped pond water through his cooling jackets and re-circulated it back into the pond. Although I'm not sure how the cooling rate difference in your molds will affect the microstructure of the parts you're pouring. That could be an issue with water.