Engineering topics
Publications and source records attributed to Mountvala, A. J..
Structural members supporting the afterburners of high thrust rocket engines are subjected to extreme heating, along with severe vibration and high acceleration levels during early lift-off. Chemically-bonded, castable, zircon composite foams were developed and successfully tested to meet specific, laboratory simulated lift-off conditions.
The effects of adsorbed H2O on the dielectric properties of ultrafine BaTiO3 particulates of varying particle size and environmental history were determined. The dielectric behavior depends strongly on surface hydration. No particle size dependence of dielectric constant was found for dehydroxylated surfaces in ultrafine particulate (unsintered) BaTiO3 materials. For equivalent particle sizes, the ac conductivity is sensitive to surface morphology. Reactions with H2O vapor appear to account for the variations in dielectric properties. Surface dehydration was effectively accomplished by washing as-received powders in isopropanol.
The properties and behavior of ceramic materials used in components for electronic circuitry are examined to appraise the present and future directions for microelectronics, and to suggest further product development, and how innovations may be useful in other technologies. Ceramic and glass insulators, resistors, capacitors, and the use of ceramics and glasses in microcircuitry are discussed along with technology transfer to nonaerospace uses.
Preparation and characteristics of lightweight refractory insulation
Surface and grain boundary properties of ceramic materials for microelectronics
Barium titanate ceramic materials applications in microelectronics
Dielectric properties of polycrystalline barium titanate ceramic materials for microelectronic applications
Lightweight ceramic foam for thermal insulation heat shields of launch structures
Foamed refractory oxides provide lightweight, reflective thermal insulation materials. The materials have a low bulk density and high thermal shock resistance.
Ceramic foam as lightweight thermal insulation for rigid heat shields in launch vehicles