What does the term 'thermal contact conductance' refer to?

Thermal contact conductance specifically refers to the rate at which heat is transferred across the interface between two materials that are in contact with each other. This parameter is critical in understanding how well heat can move from one material to another when they are in physical contact, which can significantly affect thermal management in various applications, including electronics, construction, and manufacturing.

Essentially, if two materials are in contact but have a low thermal contact conductance, there may be a significant thermal resistance at the interface, leading to inefficient heat transfer. Conversely, a high thermal contact conductance indicates that heat flows easily between the materials, allowing for better thermal connectivity. This concept is distinct from thermal insulation properties, which deal with a material's ability to resist heat flow overall, and does not pertain to how heat propagates through a single solid material.