Investigation of the phase equilibrium of the Ti-Al-Mo system in the titanium-rich alloy field
Phase equilibrium of titanium aluminum molybdenum system in titanium rich alloy field
ALUMINUM ALLOY↗
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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.
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Circadian system phase - An aspect of temporal morphology - Procedures and illustrative examples.
Circadian rhythms detection, estimating parameters by cosinor procedure for temporal morphology aspects evaluation
RESPIRATORY RATE↗
Omega phase precipitation and superconducting critical transport currents in titanium-22 at. pct niobium /columbium/.
Omega phase precipitation and superconducting crital transport currents in Ti-Nb wire samples
MAGNETIC FIELD↗
Automated Engineering Design (AED); An approach to automated documentation
The automated engineering design (AED) is reviewed, consisting of a high level systems programming language, a series of modular precoded subroutines, and a set of powerful software machine tools that effectively automate the production and design of new languages. AED is used primarily for development of problem and user-oriented languages. Software production phases are diagramed, and factors which inhibit effective documentation are evaluated.
Mcclure, C. W.↗
Space station common module power system network topology and hardware development
Candidate power system newtork topologies for the space station common module are defined and developed and the necessary hardware for test and evaluation is provided. Martin Marietta's approach to performing the proposed program is presented. Performance of the tasks described will assure systematic development and evaluation of program results, and will provide the necessary management tools, visibility, and control techniques for performance assessment. The plan is submitted in accordance with the data requirements given and includes a comprehensive task logic flow diagram, time phased manpower requirements, a program milestone schedule, and detailed descriptions of each program task.
Landis, D. M.↗
Annual Cycle of Surface Longwave Radiation
The annual cycles of upward and downward longwave fluxes at the Earth s surface are investigated by use of the NASA/GEWEX Surface Radiation Budget Data Set. Because of the immense difference between the heat capacity of land and ocean, the surface of Earth is partitioned into these two categories. Principal component analysis is used to quantify the annual cycles. Over land, the first principal component describes over 95% of the variance of the annual cycle of the upward and downward longwave fluxes. Over ocean the first term describes more than 87% of these annual cycles. Empirical orthogonal functions show the corresponding geographical distributions of these cycles. Phase plane diagrams of the annual cycles of upward longwave fluxes as a function of net shortwave flux show the thermal inertia of land and ocean.
Mlynczak, Pamela E.↗
Investigation of Ionic Liquids Isolated Iron for Ductile Iron Castings
As research continues for missions beyond low-Earth orbit, in-situ resource utilization (ISRU) methods are critical. To colonize the Lunar or Martian surface, the ability to manufacture mechanical and structural components with local resources is essential. Ionic liquids are being studied at NASA Marshall Space Flight Center (MSFC) to harvest elemental metals from meteorites and oxides in regolith. In this investigation, the viability of casting ductile iron using ionic liquids sourced iron and nickel was explored given ductile iron’s range of applications and performance as an as-cast alloy. Small ingots were produced using commercial silicon, manganese, and magnesium with carbon sourced from the by-products of a life support system currently being tested at MSFC. Samples were cast and compared to commercial ductile iron with phase transformation diagrams, microstructures, and hardness. Results showed ionic liquids sourced elements are a viable source of elemental alloying materials for a range of ductile iron alloys.
Blake Stewart↗
Investigation of Ionic Liquids Isolated Iron for Ductile Iron Castings
As research continues for missions beyond low-Earth orbit, in-situ resource utilization (ISRU) methods are critical. For Lunar and Martian colonization, the ability to manufacture mechanical and structural components with local resources is essential. Ionic liquids (IL) are being studied at NASA Marshall Space Flight Center (MSFC) to harvest elemental metals from meteorites and regolith oxides. In this investigation, the viability of casting ductile iron using ionic liquids sourced iron and nickel was explored given ductile iron’s range of applications and performance as an as-cast alloy. Ingots were produced using commercial elements to simulate the use of IL iron with carbon sourced from the by-products of a life support system currently tested at MSFC. Samples were cast and compared to commercial ductile iron with phase transformation diagrams,microstructures, and hardness. Results showed ionic liquids sourced elements are a viable source of elemental alloying materials for a range of ductile iron alloys.
Ionic Liquids↗
CALPHAD Models to Guide Refractory Alloys Additive Manufacturing: In-Situ Compounds Formation, Nanoparticles, and Impurities Considerations
This technical memorandum (TM) seeks to model and discuss aspects of nanoparticle and micrometer-scale particle or ‘microparticle’ inclusions in refractory metal alloy manufacturing, via a currently used additive manufacturing (AM) method that results in equivalent wt.% addition of dissolved elements in the melt pool composition and subsequent formation of nanometer-scale MC and MO inclusions. Additionally, the authors begin to consider the effects of oxygen (O), a ubiquitous impurity, in AM; and seek to understand a combined optimization of alloying, nano- and micro strengthening and refinement, elemental additions, and even in-situ compounds and alloys species formation. To gain insights, this TM focuses on a pair of refractory alloys currently of interest to NASA: tungsten-rhenium-tantalum carbide (with O impurities) (W-Re-TaC(-O)) and tungsten-rhenium-tantalum-carbon (with O impurities) (W-Re-Ta-C(-O)), which are processed via powder bed fusion (PBF)-SLM.
ICME integrated computational materials engineerin↗
Pioneer Venus wind experiment receiver
The final design of the Pioneer Venus Wind Experiment Receiver and Phase Calibrator is discussed from the block diagram viewpoint. Measured phase data are shown to derive the predicted performance. The STDN receiver implementation is also discussed.
Nishimura, H.↗
Measurements of antenna polar diagrams and efficiencies using a phase-switched interferometer
It is desirable to know antenna polar patterns and efficiencies accurately. In the past, calibration measurements have been made using balloons and aircraft and more recently satellites. These techniques are usually very expensive. It is shown that under certain circumstances it is possible to use a simpler and inexpensive technique by connecting together the antenna under test with another antenna to form a phase switched interferometer as first described by Ryle (1952). The technique does require a suitable radio source which gives measurable powers when using small antennas and since dipoles have broad patterns, radio sources with similar right ascensions but different declinations to the primary source can be a problem. These problems can partly be overcome by filtering the interference pattern.
Vincent, R. A.↗
Electronically Steerable Spherical Array capabilities and interfaces
The development of the Electronically Steerable Spherical Array (ESSA) was started in 1975. ESSA provides the inertialess antenna needed by user satellites for communication over their large coverage angles towards the Tracking Data Relay Satellite System (TDRSS). The performance of ESSA over large coverage angles is better than the performance provided by phased arrays. The primary difference between the two antenna types is the method of beam forming. The ESSA steers a beam by illuminating a set of elements which point in the desired direction. This set of elements is illuminated by a simple multipole switch called a switching power divider (SPD). Attention is given to details regarding the difference in performance between ESSA and phased arrays, the ESSA block diagram, the performance improvement achieved by phase compensation, power requirements, the four operating modes, multibeam operation, and the data interface.
Taylor, T. H., Jr.↗
Advanced Platform Systems Technology study. Volume 4: Technology advancement program plan
An overview study of the major technology definition tasks and subtasks along with their interfaces and interrelationships is presented. Although not specifically indicated in the diagram, iterations were required at many steps to finalize the results. The development of the integrated technology advancement plan was initiated by using the results of the previous two tasks, i.e., the trade studies and the preliminary cost and schedule estimates for the selected technologies. Descriptions for the development of each viable technology advancement was drawn from the trade studies. Additionally, a logic flow diagram depicting the steps in developing each technology element was developed along with descriptions for each of the major elements. Next, major elements of the logic flow diagrams were time phased, and that allowed the definition of a technology development schedule that was consistent with the space station program schedule when possible. Schedules show the major milestone including tests required as described in the logic flow diagrams.
Source record↗
Kinetics of the phase transformation in a Ti-15Mo-5Zr-3Al alloy as studied by X-ray diffraction
The purpose of the study is to make the T-T-T diagram available and to describe the X-ray diffraction techniques used to determine the fraction of transformed phase in the Ti-15Mo-5Zr-3Al metastable beta-alloy which decomposes into the hexagonal alpha-phase and the bcc beta-phase of a higher Mo concentration. The sheet material studied for this study is not ideal for an X-ray examination because of both a rolling and annealing texture as well as grain size problems. These difficulties are overcome using special X-ray techniques. Equations are given that indicate the approximations to be accepted if pole figure data are disregarded. Lattice parameter data from the beta phase enables one to obtain an approximate phase diagram.
Rao, V. B.↗
The Role of Rotation in the Evolution of Massive Stars
Recent evolutionary models of massive stars predict important effects of rotation including: increasing the rate of mass loss; lowering the effective gravity; altering the evolutionary track on the Hertzsprung-Russel Diagram (HRD); extending the main-sequence phase (both on the HR diagram and in time); and mixing of CNO-processed elements up to the stellar surface. Observations suggest that rotation is a more important factor at lower metallicities because of higher initial rotational velocities and weaker winds. This makes the Small Magellanic Cloud (SMC), a low-metallicity galaxy (Z=0.2 solar Z), an excellent environment for discerning the role of rotation in massive stars. We report on a FUSE+STIS+optical spectral analysis of 17 O-type stars in the SMC, where we found an enormous range in N abundances. Three stars in the sample have the same (low) CN abundances as the nebular material out of which they formed, namely C=0.085 solar C and N=0.034 solar N. However, more than half show N approx. solar N, an enrichment factor of 30X! Such unexpectedly high levels of N have ramifications for the evolution of massive stars including precursors to supernovae. They also raise questions about the sources of nitrogen in the early universe. This study was supported in part by grants from NASA's ADP, HST GO-7437, and FUSE B134.
Heap, Sara R.↗
The Low-Metallicity Galaxy, I Zw 18 (Z=1/50 Z(circle dot))
Both observations and evolutionary models indicate that rotation becomes a more important factor at lower metallicities. Some important effects of rotation include: increasing the rate of mass-loss; lowering the effective gravity; altering the evolutionary track on the Hertzsprung-Russell Diagram (HRD); extending the main-sequence phase (both on the HR diagram and in time); and mixing of CNO-processed elements up to the stellar surface. We discuss these effects for massive stars in the low-metallicity galaxy, I Zw 18 (Z=1/50 Z(circle dot)) and their implications for the first stars.
Heap, Sara R.↗
High resolution angular sensor
Specifications for the pointing stabilization system of the large space telescope were used in an investigation of the feasibility of reducing ring laser gyro output quantization to the sub-arc-second level by the use of phase locked loops and associated electronics. Systems analysis procedures are discussed and a multioscillator laser gyro model is presented along with data on the oscillator noise. It is shown that a second order closed loop can meet the measurement noise requirements when the loop gain and time constant of the loop filter are appropriately chosen. The preliminary electrical design is discussed from the standpoint of circuit tradeoff considerations. Analog, digital, and hybrid designs are given and their applicability to the high resolution sensor is examined. the electrical design choice of a system configuration is detailed. The design and operation of the various modules is considered and system block diagrams are included. Phase 1 and 2 test results using the multioscillator laser gyro are included.
Gneses, M. I.↗
Phase relations in the Fe-Ni-Cr-S system and the sulfidation of an austenitic stainless steel
The stability fields of various sulfide phases that form on Fe-Cr, Fe-Ni, Ni-Cr and Fe-Cr-Ni alloys were developed as a function of temperature and the partial pressure of sulfur. The calculated stability fields in the ternary system were displayed on plots of log P sub S sub 2 versus the conjugate extensive variable which provides a better framework for following the sulfidation of Fe-Cr-Ni alloys at high temperatures. Experimental and estimated thermodynamic data were used in developing the sulfur potential diagrams. Current models and correlations were employed to estimate the unknown thermodynamic behavior of solid solutions of sulfides and to supplement the incomplete phase diagram data of geophysical literature. These constructed stability field diagrams were in excellent agreement with the sulfide phases and compositions determined during a sulfidation experiment.
Jacob, K. T.↗