There are a number of pressureless casting techniques available. Investment casting is widely used, for instance. https://www.harmonycastings.com/ is a fancier example.
For this specific application, the manufacturing method determines the porosity of the material, and therefore the heat transfer.
CNC prototype parts will have better heat transfer than pressure die cast, and the pressure die cast will perform better than pressureless cast parts.
For this specific application, the manufacturing method determines the porosity of the material, and therefore the heat transfer.
CNC prototype parts will have better heat transfer than pressure die cast, and the pressure die cast will perform better than pressureless cast parts.