Materials

A document presents a study of why materials of composition (Ag1–ySbTe2)0.05 (PbTe)0.95 [0≤y≤1] were previously reported to have values of the thermoelectric figure of merit [ZT (where Z =α2/ρκ, α is the Seebeck coefficient, ρ is electrical resistivity, κ is...

Patches consisting mostly of ceramic fabrics impregnated with partially cured polymers and ceramic particles are being developed as means of repairing ceramics and ceramic-matrix composites (CMCs) that must withstand temperatures above the melting points of refractory metal alloys. These...

Dispersions (including monodispersions) of nanotubes in water at relatively high concentrations have been formulated as prototypes of reagents for use in making fibers, films, and membranes based on single-walled carbon nanotubes (SWNTs). Other than water, the ingredients of a dispersion of this...

Silica aerogels have been shown to be attractive for use as thermal insulation materials for thermoelectric devices. It is desirable to thermally insulate the legs of thermoelectric devices to suppress lateral heat leaks that degrade thermal efficiency. Aerogels offer not only high thermal...

A paper discusses an experimental regenerable sorber for removing CO2 and trace components — principally, volatile organic compounds, halocarbons, and NH3 — from spacecraft cabin air. This regenerable sorber is a prototype of what is intended to be a lightweight alternative to...

Microsphere insulation panels (MIPs) have been developed as lightweight, long lasting replacements for the foam and vacuum-jacketed systems heretofore used for thermally insulating cryogenic vessels and transfer ducts. Whether preformed or applied in place, foam insulation deteriorates fairly rapidly: on cryogenic...

ASelf-propagating high-temperature combustion synthesis (SHS) is the basis of a method of making components of porous tricalcium phosphate [Ca3(PO4)2] and related compounds in net sizes and shapes for use as surgical implants that are compatible with bone. Ca3(PO4)2-based materials...

“Methane to aromatics on Mars” (“METAMARS”) is the name of a process originally intended as a means of converting Martian atmospheric carbon dioxide to aromatic hydrocarbons and oxygen, which would be used as propellants for spacecraft to return to Earth. The process has been...

Environmentally benign, biodegradable structures for supporting growing plants can be made in a process based on recycling of such waste plant fiber materials as wheat straw or of such derivative materials as paper and cardboard. Examples of structures that can be made in this way include plant...

A document discusses a proposal to use advanced materials — especially bulk metallic glass (BMG) foams — in structural components of spacecraft, lunar habitats, and the like. BMG foams, which are already used on Earth in some consumer products, are superior to conventional metal foams: BMG foams...

Improved small-particle powders and powder-processing conditions have been developed for use in plasma spray deposition of thermal-barrier and environmentalbarrier coatings. Heretofore, plasmasprayed coatings have typically ranged in thickness from 125 to 1,800 µm. As explained below, the...