High temperature refractory member with radiation emissive overcoat

摘要

A radiation type heat dissipator for use in a plasma engine is formed of a refractory metal layer upon which there is deposited a radiation emissive coating made of a high emissivity material such as zirconium diboride. The radiation emissive coating has a surface emissivity coefficient substantially greater than the emissivility coefficient of the refractory metal and thereby enhances the optical radiating efficiency of the heat dissipator.