Copper and Led metallurgy

Since pressure die casting or gravity die casting are ruled out in this case suggest to look

>Increase the thickness of the component (if design constraints are not there)

>Make sure that the leakage is only because of the component and no open wells.

>Try combining with Aluminium which as equally good therrmal properties

>Try rotational / Centrifugal casting if the component is cylindrical ( since led density is more, this will help in uniform mixing of the same)

Also from my experience, the metallurgical combination is not a viable one I guess.

I will add that X-rays in of themselves are blocked by lead quite well, but the problem is that many other materials when bombarded with x-rays will give off neutrons. Polyethylene acts to slow the neutron gradually instead of slowing it abruptly, thereby eliminating the ability of the neutron to transmute the lead.

You can read more about that kind of radiation here:

http://en.wikipedia.org/wiki/Braking_radiation

You could spray the mold surfaces with a tungsten alloy then continue the molding process. The shell that would be left on the outside of the part would have good conductive properties and would also prevent any lead migration from the part. This also provides extra containment as well as offering a finished looking part.

I would try a vacuum degas before pouring the casting. Remove all slag and heat the molds as porosity can be caused by shrinkage if it cools the melt too fast.

Can you hold the melt long enough to get an analysis? Sometimes variations in composition can worsen the effect.

If specific areas are a problem, look into putting a heat sinking material in the mold. You will have to research this as I don't remember 35 years back very well any more.

One other thing, I also used to repair some casting defects with a method called "spray welding" which involved grinding out the defect and using an oxy-acetylene torch with a cannister of flux and powdered mix of the alloy. The unit had a way of feeding the powder into the flame. This was nodular iron and the defects were found with ultrasonic test instruments. The repairs were typically higher quality than the casting.

fill from below into a water-cooled Pure Copper Split mould.

Porosity will vanish

Your problems --gone