Materials & Coatings

Thermal-barrier coatings (TBCs) that have both initial and post-exposure thermal conductivities lower than those of yttria-stabilized zirconia TBCs have been developed. TBCs are thin ceramic layers, generally applied by plasma spraying or physical vapor deposition, that are used to insulate air-cooled...

A pre-operational annealing process is under investigation as a potential means of preventing a sudden reduction of ionic conductivity in a β"—alumina solid electrolyte (BASE) during use. On the basis of tests described below, the sudden reduction of ionic conductivity, followed by a slow...

A reactive-ion etching (RIE) process has been developed to enable the formation of holes with steep sidewalls in a layer of silicon dioxide that covers a silicon substrate. The holes in question are through the thickness of the SiO2 and are used to define silicon substrate areas to be...

A process for growing protein crystals encapsulated within membranes has been invented. This process begins with the encapsulation of a nearly saturated aqueous protein solution inside semipermeable membranes to form microcapsules. The encapsulation is effected by use of special formulations of a dissolved...

Electrode materials that exhibit mixed conductivity (that is, both electronic and ionic conductivity) have been investigated in a continuing effort to improve the performance of the alkali metal thermal-to-electric converter (AMTEC). These electrode materials are intended primarily for use on the...

Electrolytes comprising LiPF6 dissolved at a concentration of 1.0 M in three different mixtures of alkyl carbonates have been found well suited for use in rechargeable lithium-ion electrochemical cells at low temperatures. These and other electrolytes have been investigated in continuing...

Special foam pads have been developed for use in helmets. The foams in these pads have been formulated to obtain a combination of light weight, resistance to oxidation, flame retardance, superior shock-absorbing properties, and physical comfort during long use. In the original application, the pads are intended...

Water-borne, silicone- based paints for protecting metal structures against corrosion have been developed as substitutes for traditional anticorrosion paints that contain large amounts of volatile organic solvents. It is desirable to reduce the volatile-organic-compound (VOC) contents of paints in...

Lightweight, refractory ceramic/carbon thermal-insulation materials have been invented. These materials, consist of carbon, silicon, and oxygen in suitable pro- portions combined into molecular structures that are stable at high temperatures. Insulating tiles and other components made of...

A paper presents a study of multilayer thermal insulations for protecting spacecraft against aerodynamic heating during reentry into a planetary atmosphere. A multilayer insulation considered in the study comprised (1) thin ceramic/composite foils coated with gold for high reflectance...

An improved method of inserting reactive material in the ground for treating groundwater contaminated with chlorinated solvents has been devised. An older method involves the removal of a significant portion of soil overlying the treatment volume, and consequently the expensive off-site...

A report proposes a high-temperature- resistant solar sail with an areal mass density less than 1 g/m2, for a spacecraft that would approach the Sun to within a distance of 0.2 astronomical unit (≈3 × 107 km). The sail would be made in multiple segments of a carbon microtruss fabric...

A report describes the completed first phase of a NASA/industry cooperative program of research on metal-matrix composites (MMCs) as lightweight, strong, high- temperature-resistant materials for use in future aircraft engines. The first phase of the research included assessment of life- and...