What material(s) are high in thermal conductivity but electrically inert?

Question

Any commonly used, inexpensive materials fit this description?

Answer 1

This is a common problem in electronics. Designers want to transfer heat from the part to the heat sink and still be electrically isolated. They used to use a thin mica insulaor with a thin silicone coating, but these days they use thin silicone sheeting. The heat transfer is still way below direct metal contact.

There are heat conducting epoxies, but they are hard to use and expensive.

There is a certain ceramic that conducts heat almost as well as metals, but it is expensive and hazardous. They no longer make it in America.

The final answer is no, there is no cheap easy solution.

Answer 2

Sand

Answer 3

distilled water

Answer 4

glass