Any real world experience using lithium or boron copper to degas copper or nickel copper? I'm looking to maintain thermal conductivity in water blocks. From ASM Chapter 15, Cast Copper and Copper Alloys: Electrical and thermal conductivity of any casting will invariably be lower than for wrought metal of the same composition. Copper castings are used in the electrical industry for their current-carrying capacity, and they are used for water-cooled parts of melting and refining furnaces because of their high thermal conductivity. However, for a copper casting to be sound and have electrical or thermal conductivity of at least 85%, care must be taken in melting and casting. The ordinary deoxidizers (silicon, tin, zinc, aluminum, and phosphorus) cannot be used because small residual amounts lower electrical and thermal conductivity drastically. Calcium boride or lithium will help to produce sound castings with high conductivity. Belmont sells Lithium and Boron Copper https://www.belmontmetals.com/product-category/lithium-copper/ https://www.belmontmetals.com/product/2-boron-copper/
I have some elemental Boron and tried it once to alloy a bit of B with copper which did work. Phosphorus copper I did also make by adding a mixture of NaPO3 + silica sand and aluminum powder wrapped in a piece of thin copper sheet and immersing this into the liquid copper. This mixture reacts above 700 C and releases gaseous P which will be absorbed by the Cu as it is immersed in the liquid metal and cannot be in contact with air. I also have Li metal, but adding this to liquid copper will burn it away and also vaporize it as the boiling point of Li is below the melting point of Cu.
Thanks for the reply. I believe the lithium reaction is intended to vaporize and along the way, combine with hydrogen and oxygen in solution. From ASM again: The specific chemical reactions that can occur with lithium include: 2Li Cu2O → 2Cu Li2O (deoxidation) Li H → LiH (degassing) LiH Cu2O → 2Cu LiOH (recombination) 2Li H2O → Li2O H2 (reaction during pouring) The lithium oxide (Li2O) and lithium hydroxide (LiOH) products separate cleanly as a low density fluid slag suitable for skimming (Ref 19). The lithium hydride that forms initially if hydrogen is present is unstable at normal copper melting temperatures and recombines with cuprous oxide (recombination).
