Materials & Coatings

A report presents results of research on carbonate-based electrolytes to improve the low-temperature-performances of lithium-ion rechargeable electrochemical cells. The loss of performance with decreasing temperature is attributable largely to a decrease of ionic conductivity and the increase...

The Materials Science Division (MSD) at Kennedy Space Center is developing a computer system to maintain a material-science data base coupled with a user-friendly interface on the World Wide Web. The system is designed to eliminate the need for time-consuming and expensive distribution of,...

In a proposed method of tailoring some of the mechanical properties of metal-matrix, oxide-matrix, and ceramic-matrix composite materials, Kirkendall defects (microscopic pores as described below) would be introduced into thin interfacial layers between the fibers and the matrices. This...

Coating alumina fibers with sputtered metal has been proposed as a means to enable the fibers to retain more strength when the fibers are incorporated into metal-matrix composites. If the alumina fibers could be made to retain more strength, then it would be possible to manufacture such...

A report presents updated information on the developments described in "MoSi2-Based Composite Materials for Aircraft Engines" (LEW-16617),NASA Tech Briefs, Vol. 22, No. 9 (September 1998), page 62. To recapitulate: Hybrid composites of (1) SiC-based fibers within (2) matrices that...

Probabilistic Ceramic Matrix Composite Analyzer (PCEMCAN) is a user-friendly computer program that predicts uncertainties in the mechanical and thermal properties of ceramic-matrix composite (CMC) materials. These materials are candidates for fabrication of structural components that will be...

The figure shows a prototype of a magnetostrictively actuated mechanism that would rotate an optical filter wheel for a high-performance infrared camera or telescope. Typically, a high-performance infrared instrument and its filter wheel are operated inside a cryogenic system. In conventional practice, the...

A process that is undergoing development would be used to mass-produce textured polycrystalline rods of a terbium/dysprosium alloy for cryogenic magnetostrictive actuators. The rolling-and-heat-treatment process described in the preceding article yields a high degree of crystal orientation, but is...

The differential miscibility of castor oil in ethanol and water would be exploited to separate ethanol from water, according to a proposal. Burning the separated ethanol would produce more energy than would be consumed in the separation process. In contrast, the separation of a small amount...

The differential solubility of sulfur in ethanol and water could be exploited to separate ethanol from water. The energy that could be produced by burning the separated ethanol would be more than that required in the separation process. In contrast, the separation of a small amount of...