Hello, everyone! I’ll say right away that I’m not very familiar with 3D printing, although I have worked with plastic. I’m more in the metalworking field. So here’s my idea: printing a 3D object with small holes inside, possibly in the form of a mesh or hexagon. Creating such a micro-porous structure with the smallest possible gaps. Then cover this structure with liquid metal, the main thing is to use plastic or print settings for better adhesion.
After all these procedures, you can start galvanizing the part. For example, using chrome or copper. This will make the structure stronger and, in theory, able to withstand high temperatures and pressures.
Yes, using the best filament for the application should be the first step. In most cases that’s enough. And yes, doing a composite layup would be a lot of work. If one were to go that rout, it may make more sense to print a mold and make the part in composite, perhaps filling with “forged” fiber or leaving it hollow.