SEARCH · Search NASA

Results for “Metallic systems”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22

All sources NASA NTRS DOE OSTI

NASA NTRS2017

Systems and Methods for Fabricating Objects Including Amorphous Metal Using Techniques Akin to Additive Manufacturing

Systems and methods in accordance with embodiments of the invention fabricate objects including amorphous metals using techniques akin to additive manufacturing. In one embodiment, a method of fabricating an object that includes an amorphous metal includes: applying a first layer of molten metallic alloy to a surface; cooling the first layer of molten metallic alloy such that it solidifies and thereby forms a first layer including amorphous metal; subsequently applying at least one layer of molten metallic alloy onto a layer including amorphous metal; cooling each subsequently applied layer of molten metallic alloy such that it solidifies and thereby forms a layer including amorphous metal prior to the application of any adjacent layer of molten metallic alloy; where the aggregate of the solidified layers including amorphous metal forms a desired shape in the object to be fabricated; and removing at least the first layer including amorphous metal from the surface.

Hofmann, Douglas↗

NASA NTRS1978

Gain measurements of the Ca-Xe charge exchange system

Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

Michels, C. J.↗

NASA NTRS1979

Research in structures and materials for future space transportation systems - An overview

The paper provides a review of some of the advances of the past decade in structures and materials that have application to future space transportation systems. The paper concentrates on metallic thermal protection systems and structures which could provide the structural efficiency, reliability, and durability dictated by future space utilization requirements. The need for completely reusable, on-board cryogenic fuel tanks is cited as the most challenging technical opportunity and potential thermostructural concepts for tanks are identified. Other critical areas needing technology advances are discussed. Finally, the unique research opportunities offered by the Shuttle Orbiter experiments program for testing structures and thermal protection systems are explored.

Kelly, H. N.↗

NASA NTRS2000

NASA Information Technology Implementation Plan

NASA's Information Technology (IT) resources and IT support continue to be a growing and integral part of all NASA missions. Furthermore, the growing IT support requirements are becoming more complex and diverse. The following are a few examples of the growing complexity and diversity of NASA's IT environment. NASA is conducting basic IT research in the Intelligent Synthesis Environment (ISE) and Intelligent Systems (IS) Initiatives. IT security, infrastructure protection, and privacy of data are requiring more and more management attention and an increasing share of the NASA IT budget. Outsourcing of IT support is becoming a key element of NASA's IT strategy as exemplified by Outsourcing Desktop Initiative for NASA (ODIN) and the outsourcing of NASA Integrated Services Network (NISN) support. Finally, technology refresh is helping to provide improved support at lower cost. Recently the NASA Automated Data Processing (ADP) Consolidation Center (NACC) upgraded its bipolar technology computer systems with Complementary Metal Oxide Semiconductor (CMOS) technology systems. This NACC upgrade substantially reduced the hardware maintenance and software licensing costs, significantly increased system speed and capacity, and reduced customer processing costs by 11 percent.

Source record↗

NASA NTRS1987

Selection of high temperature thermal energy storage materials for advanced solar dynamic space power systems

Under the direction of NASA's Office of Aeronautics and Technology (OAST), the NASA Lewis Research Center has initiated an in-house thermal energy storage program to identify combinations of phase change thermal energy storage media for use with a Brayton and Stirling Advanced Solar Dynamic (ASD) space power system operating between 1070 and 1400 K. A study has been initiated to determine suitable combinations of thermal energy storage (TES) phase change materials (PCM) that result in the smallest and lightest weight ASD power system possible. To date the heats of fusion of several fluoride salt mixtures with melting points greater than 1025 K have been verified experimentally. The study has indicated that these salt systems produce large ASD systems because of their inherent low thermal conductivity and low density. It is desirable to have PCMs with high densities and high thermal conductivities. Therefore, alternate phase change materials based on metallic alloy systems are also being considered as possible TES candidates for future ASD space power systems.

Lacy, Dovie E.↗

NASA NTRS1987

Selection of high temperature thermal energy storage materials for advanced solar dynamic space power systems

Lacy, Dovie E.↗

NASA NTRS2009

Liquid Oxygen Rotating Friction Ignition Testing of Aluminum and Titanium with Monel and Inconel for Rocket Engine Propulsion System Contamination Investigation

Metallic contaminant was found in the liquid oxygen (LOX) pre-valve screen of the shuttle main engine propulsion system on two orbiter vehicles. To investigate the potential for an ignition, NASA Johnson Space Center White Sands Test Facility performed (modified) rotating friction ignition testing in LOX. This testing simulated a contaminant particle in the low-pressure oxygen turbo pump (LPOTP) and the high-pressure oxygen turbo pump (HPOTP) of the shuttle main propulsion system. Monel(R) K-500 and Inconel(R) 718 samples represented the LPOTP and HPOTP materials. Aluminum foil tape and titanium foil represented the contaminant particles. In both the Monel(R) and Inconel(R) material configurations, the aluminum foil tape samples did not ignite after 30 s of rubbing. In contrast, all of the titanium foil samples ignited regardless of the rubbing duration or material configuration. However, the titanium foil ignitions did not propagate to the Monel and Inconel materials.

Peralta, S.↗

NASA NTRS1991

Low cost battery designs for small satellite applications

The topics are presented in viewgraph form and include the following: EPI nickel-hydrogen flight history; designs developed and tested; 3.5 inch diameter common pressure vessel (CPV); nickel-hydrogen system advantages; 2.5 inch diameter individual pressure vessel (IPV) and CPV; 5 AH CPV charge voltage/pressure; 5 AH CPV cell design; RNH-5-1 charge retention test; nickel-hydrogen cell specifications; sealed prismatic nickel metal hydride; nickel metal hydride life test; nickel-hydride cell specifications; and nickel metal hydride system advantages.

Brill, Jack↗

NASA NTRS1979

Effect of interfacial species on shear strength of metal-sapphire contacts

The interfacial shear strength of the metal-insulator system has been studied by means of the coefficient of static friction of copper, nickel, or gold contacts on sapphire in ultrahigh vacuum. The effect on contact strength of adsorbed oxygen, nitrogen, chlorine, and carbon monoxide on the metal surfaces is reported. It was found that exposures as low as 1 L of O2 on Ni produced observable increases in contact strength, whereas exposures of 3 L of Cl2 lead to a decrease in contact strength. These results imply that submonolayer concentrations of these species at the interface of a thin Ni film on Al2O3 should affect film adhesion similarly. The atomic mechanism by which these surface or interface phases affect interfacial strength is not yet understood.

Pepper, S. V.↗

NASA NTRS1960

Landing Energy Dissipation for Manned Reentry Vehicles

Analytical and experimental investigations have been made to determine the landing-energy-dissipation characteristics for several types of landing gear for manned reentry vehicles. The landing vehicles are considered in two categories: those having essentially vertical-descent paths, the parachute-supported vehicles, and those having essentially horizontal paths, the lifting vehicles. The energy-dissipation devices discussed are crushable materials such as foamed plastics and honeycomb for internal application in couch-support systems, yielding metal elements as part of the structure of capsules or as alternates for oleos in landing-gear struts, inflatable bags, braking rockets, and shaped surfaces for water impact. It appears feasible to readily evaluate landing-gear systems for internal or external application in hard-surface or water landings by using computational procedures and free-body landing techniques with dynamic models. The systems investigated have shown very interesting energy-dissipation characteristics over a considerable range of landing parameters. Acceptable gear can be developed along lines similar to those presented if stroke requirements and human-tolerance limits are considered.

Fisher, Lloyd J., Jr.↗

NASA NTRS1993

Diffusion in liquid state and solidification of binary system (M-7)

Diffusion is one of the most fundamental physical phenomena. It relates to the manufacturing of almost all materials. Therefore, the precise knowledge of diffusivities of relevant materials is necessary for the optimization of these processes. On the other hand, such knowledge is indispensable to understanding the diffusion mechanism and structure of liquid metal in the field of physical metallurgy. Many diffusion experiments on solid metal were undertaken and a lot of data were accumulated. But on liquid metals there are few measurements because of experimental difficulties, such as thermal convection, induced by very slight temperature gradients in the specimen. Under microgravity conditions, the movement of liquid metal due to density differences and thermal convection must be suppressed markedly. Therefore, the transportation process will be controlled only by the diffusion of constituent atoms. These conditions offer the optimum environments for the diffusion experiment. The experiments are briefly described. Diffusion couples are prepared by attaching end to end two rods of different pure metals using hot press equipment. These couples are inserted into a graphite crucible and then doubly enclosed by two silica ampoules, respectively. The specimen is inserted into a tantalum cartridge, which is welded in a vacuum using an electron-beam apparatus. These cartridges are charged in the continuous heating furnace in space and held at a given temperature for a predetermined time and then solidified. The concentration distribution of elements in these specimens will be measured along the rod axis by means of an electron probe microanalyzer. The counterdiffusivity of the liquid metal binary system is determined on the basis of the compensated concentration distribution profile for thermal contraction.

Dan, T.↗

NASA NTRS2019

Systems and Methods for Structurally Interrelating Components Using Inserts Made from Metallic Glass-Based Materials

Systems and methods in accordance with embodiments of the invention operate to structurally interrelate two components using inserts made from metallic glass-based materials. In one embodiment, a method of structurally interrelating two components includes: forming an insert from a metallic glass-based composition; where the formed insert includes a metallic glass-based material; affixing the insert to a first component; and structurally interrelating the second component to the first component using the insert.

Hofmann, Douglas C.↗

NASA NTRS1973

Design and testing of a passive, feedback-controlled, variable conductance heat pipe

A passive feedback system, which stabilizes the heat source temperature (T sub s) of a gas loaded heat pipe, was designed and tested. The control of T sub s is accomplished by an auxiliary liquid that senses the heat source and actuates a metal bellows system due to the liquid's thermal expansion. The movement of the bellows varies the gas reservoir volume and leads to a corresponding change of the condensation area of the heat pipe. With methanol as the heat pipe working fluid and perfluoro-n-pentane as the auxiliary liquid, the control capability was found to be T sub s = 31.5 + or - 1.5 C in a power range from 3 to 30 W, compared to T sub s = 33 + or - 3 C with methanol as auxiliary liquid. The change in T sub s was 35 + or - 5.5 C with the bellows held in the closed position.

Schlitt, K. R.↗

NASA NTRS2007

Ceramic Integration Technologies for Aerospace and Energy Systems: Technical Challenges and Opportunities

Ceramic integration technology has been recognized as an enabling technology for the implementation of advanced ceramic systems in a number of high-temperature applications in aerospace, power generation, nuclear, chemical, and electronic industries. Various ceramic integration technologies (joining, brazing, attachments, repair, etc.) play a role in fabrication and manufacturing of large and complex shaped parts of various functionalities. However, the development of robust and reliable integrated systems with optimum performance requires the understanding of many thermochemical and thermomechanical factors, particularly for high temperature applications. In this presentation, various challenges and opportunities in design, fabrication, and testing of integrated similar (ceramic-ceramic) and dissimilar (ceramic-metal) material systems will be discussed. Experimental results for bonding and integration of SiC based LDI fuel injector, high conductivity C/C composite based heat rejection system, solid oxide fuel cells system, ultra high temperature ceramics for leading edges, and ceramic composites for thermostructural applications will be presented. Potential opportunities and need for the development of innovative design philosophies, approaches, and integrated system testing under simulated application conditions will also be discussed.

Singh, Mrityunjay↗

NASA NTRS1991

Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

NASA Program Environmental Health↗

NASA NTRS1999

Parametric Weight Comparison of Current and Proposed Thermal Protection System (TPS) Concepts

A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (1 -D) thermal finite element sizing code. This sizing code contained models to ac- count for coatings, fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) rocket-powered single-stage-to-orbit (SSTO) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a particular trajectory. Eight TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile systems and approaches blanket TPS weights for higher integrated heat loads.

Myers, David E.↗

NASA NTRS2010

Formula for the Removal and Remediation of Polychlorinated Biphenyls in Painted Structures

An activated metal treatment system (AMTS) removes and destroys polychlorinated biphenyls (PCBs) found in painted structures or within the binding or caulking material on structures. It may be applied using a "paint-on and wipe-off" process that leaves the structure PCB-free and virtually unaltered in physical form. AMTS is used in conjunction with a solvent solution capable of donating hydrogen atoms. AMTS as a treatment technology has two functions: first, to extract PCBs from the material, and second, to degrade the extracted PCBs. The process for removing PCBs from structures is accomplished as an independent step to the degradation process. The goal is to extract the PCBs out of the paint, without destroying the paint, and to partition the PCBs into an environmentally friendly solvent. The research to date indicates this can be accomplished within the first 24 hours of AMTS contact with the paint. PCBs are extremely hydrophobic and prefer to be in the AMTS over the hardened paint or binder material. The solvent selected must be used to open, but not to destroy, the paint s polymeric lattice structure, allowing pathways for PCB movement out of the paint and into the solvent. A number of solvent systems were tested and are available for use within the AMTS. The second process of the AMTS is the degradation or dehalogenation of the PCBs. The solvent selection for this process is limited to solvents that are capable of donating a hydrogen atom to the PCB structure. Additional AMTS formulation properties that must be addressed for each site-specific application include viscosity and stability. The AMTS must be thick enough to remain where it is applied. Several thickening agents have been tested. Adding a stabilizing agent ensures that the AMTS will not evaporate and leave unprotected, activated metal exposed. During AMTS formulation testing, a number of reagents were evaluated to ensure the rate of dehalogenation was not inhibited by its addition to the system.

Quinn, Jacqueline↗

NASA NTRS1985

Graphite fiber reinforced thermoplastic glass matrix composites for use at 1000 F

The fabrication and properties of the graphite fiber reinforced glass matrix composite system are described. By reinforcing borosilicate glass with graphite fibers it has been possible to develop a composite whose properties can be compared favorably with resin matrix counterparts. Both high elastic modulus and strength can be obtained and maintained to temperatures of approximately 600 C. In addition, composite dimensional stability is superior to resin or metal matrix systems due to the low thermal expansion behavior of the glass matrix.

Prewo, K. M.↗