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In a number of areas the Army has need for high-0temperature, heat-shielding materials that retain shape and structural integrity in severe thermal environments. Some applications are the throat of a jet engine or the interior of a rocket combustion chamber. We have been examining the response of a number of corn-posite materials to a high-energy-flux environment using a welding laser instead of the arc furnaces of earlier studies. A laser is a clean, well-defined energy source. If used with an air stream or an exhaust system to remove pyrolytic products and debris, we can isolate the action of energy flux from secondary effects and reduce scatter in data., Typical of the structural forms we have tested are foams, fabric-reinforced composites and bulk graphite. Silica or carbon microballoons or fabric reinforce the newer high-temperature resins in samples we have compared with ATJ and pyrolytic graphites. A sampling of ablation results are shown in Table I. Among these materials, two are outstanding, both as thermal barriers and in retention of structural integrity. These are pyrolytic graphite and TBR. The former is a form of bulk graphite deposited at high-temperature on a substrate from a carbonaceous gas, e.g., methane. The latter is a relatively new material fabricated from carbon cloth and a Hitco proprietary resin. Both have a laminar structure. FABRICATION OF TBR j "The class of materials known as TBR, an acronym for tungsten-bearing resins, is made by impregnating layers of carbon cloth with a resin containing tungsten atoms chemically bound within the polymer backbone. The laminate is then cured, carbonized, and j fired to a graphitizing temperature producing a carbon in tungsten carbide composite. At this temperature, the tungsten carbides sinter and bond the layers of carbon fabric together. The outstanding behavior of TER composites has raised4 & questions as to how and why it outperforms other composites as wel