The high melting point (475O° F) and comparatively large potential supply of molybdenum suggest that this metal may be useful at temperatures above the melting points of most metals and alloys. In order to use it at high temperatures in the presence of oxygen, however, the molybdenum must be protected against oxidation, and hence it is logical to apply a protective ceramic coating. Several such coatings were developed and applied in the form of water suspensions or "slips" to specimens of molybdenum, by dipping or spraying, after which the pieces were dried and fired at a temperature of 2150° F in oxygen-free atmospheres. Tests of the coated pieces included (l) heating in a gas-oxygen flame, (2) heating at constant temperature in an air atmosphere, (3) thermal-shock tests, and （4） service testing of parts that were finished with a selected ceramic coating in the blast of ram-jet engines.
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