Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “material science”

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.

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

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Publishing Challenges in Energetic Materials Science

The editorial addressed the ethical dilemma that energetic materials scientists face in advancing their field for societal good and not providing information that could be used for nefarious purposes. The reaction to the editorial was heated, both pro and con. Here we concluded that PEP had done a good job in catalyzing a thoughtful debate in our community about what information should or should not be published.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1975

Manufacturing in space and materials sciences on Skylab

Two main groups of manufacturing and materials studies were performed during the Skylab missions. The first group of experiments studied processes which are important in orbital assembly and construction, including melting, solidification, brazing, welding, and cutting. The second group concerned the manufacture of specific materials, including metallic alloys, single crystals, doped semiconductors, composite materials, and multicomponent superconductors. The present paper discusses several specific experiments conducted on Skylab. In general, the processes tested produced materials of higher quality in space than they would have on earth. The experiments prove that the elimination of gravitational forces has a decisive effect on a number of materials processes.

Stuhlinger, E.↗
NASA NTRS1999

Material Science Experiments on Mir

This paper describes the microgravity materials experiments carried out on the Shuttle/Mir program. There were six experiments, all of which investigated some aspect of diffusivity in liquid melts. The Liquid Metal Diffusion (LMD) experiment investigated the diffusivity of molten Indium samples at 185 C using a radioactive tracer, In-114m. By monitoring two different gamma ray energies (190 keV and 24 keV) emitted by the samples it was possible to measure independently the diffusion rates in the bulk and at the surface of the samples. The Queens University Experiment in Liquid Diffusion (QUELD) was the furnace facility used to process 213 samples for the five other experiments. These experiments investigated the diffusion, ripening, crystal growth, and glass formation in metal, semiconductor, and glass samples. This facility had the capability to process samples in an isothermal or gradient configuration for varying periods of time at temperatures up to 900 C. Both the LMD and the QUELD furnaces were mounted on the Microgravity Isolation Mount (MIM) which provided isolation from g-jitter. All the microgravity experiments were supported by the Space Acceleration Measurement System (SAMS); a three head three axes acceleration monitoring system which measured and recorded the acceleration environment.

Kroes, Roger L.↗
DOE OSTI2020

High-Energy X-Ray Diffraction Microscopy in Materials Science

High-energy diffraction microscopy (HEDM) is an implementation of three-dimensional X-ray diffraction microscopy. HEDM yields maps of internal crystal orientation fields, strain states, grain shapes and locations as well as intragranular orientation distributions, and grain boundary character. Because it is nondestructive in hard materials, notably metals and ceramics, HEDM has been used to study responses of these materials to external fields including high temperature and mechanical loading. Currently available sources and detectors lead to a spatial resolution of ~1 μm and an orientation resolution of <0.1°. With the penetration characteristic of high energies ( E ≥ 50 keV), sample cross-section dimensions of ~1 mm can be studied in materials containing elements across much of the Periodic Table. This review describes hardware and software associated with HEDM as well as examples of applications. Overall, these applications include studies of grain growth, recrystallization, texture development, orientation gradients, deformation twinning, annealing twinning, plastic deformation, and additive manufacturing. We also describe relationships to other X-ray-based methods as well as prospects for further development.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Dynamic Mesoscale Materials Science at the Advanced Photon Source [Slides]

We are modernizing our 1980s nuclear deterrent, and moving beyond life extensions (W76, B61, W88) to systems that have more newly (differently) manufactured components (W80, W87). For the first time since the 1980s, we are doing truly new designs (W93) and there will likely be more to respond to emerging deterrence gaps.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Review of low-cost self-driving laboratories in chemistry and materials science: the “frugal twin” concept

This review proposes the concept of a “frugal twin,” similar to a digital twin, but for physical experiments. Frugal twins range from simple toy examples to low-cost surrogates of high-cost research systems. For example, a color-mixing self-driving laboratory (SDL) can serve as a low-cost version of a costly multi-step chemical discovery SDL. Frugal twins already provide hands-on experience for SDLs with low costs and low risks. They can also offer as test beds for software prototyping (e.g., optimization, data infrastructure), and a low barrier to entry for democratizing SDLs. However, there is room for improvement. The true value of frugal twins can be realized in three core areas. Firstly, hardware and software modularity; secondly, purpose-built design (human-inspired vs. hardware-centric vs. human-in-the-loop); and thirdly state-of-the-art (SOTA) software (e.g., multi-fidelity optimization). We also describe the ethical benefits and risks that come with the democratization of science through frugal twins. For future work, we suggest ideas for new frugal twins, SDL educational course outcomes, and a classification scheme for autonomy levels.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Discrete event cellular automata: A new approach to cellular automata for computational material science

Here, we explore the computational advantages of discrete event simulation for cellular automata models of grain growth. These benefits include a reduction in execution time by up to an order of magnitude and the elimination of numerical errors that stem from overshooting grain capture events and approximating a Poisson process with a Bernoulli process. The fundamental mechanisms speeding up the discrete event simulation are uncovered, and with these we create a speedup model that explains our experimental outcomes.

36 MATERIALS SCIENCE↗
DOE OSTI2023

EXSCLAIM!: Harnessing materials science literature for self-labeled microscopy datasets

This work introduces the EXSCLAIM! toolkit for the automatic extraction, separation, and caption-based natural language annotation of images from scientific literature. EXSCLAIM! is used to show how rule-based natural language processing and image recognition can be leveraged to construct an electron microscopy data set containing thousands of keyword-annotated nanostructure images. Moreover, it is demonstrated how a combination of statistical topic modeling and semantic word similarity comparisons can be used to increase the number and variety of keyword annotations on top of the standard annotations from EXSCLAIM! With large-scale imaging datasets constructed from scientific literature, users are well positioned to train neural networks for classification and recognition tasks specific to microscopy-tasks often otherwise inhibited by a lack of sufficient annotated training data.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Materials Science of the Interstitial Doping Process

Particle accelerators are an increasingly important tool for frontier science. Growing initial and operating costs are a significant barrier for upgrades and for new machines. While everything matters, the major cost contributor is the SRF cavities and their ancillary facilities (e.g., cryoplant). Accordingly, the accelerator science community devotes much R&D effort to improving their energy efficiency (increased Q o ) and gradient (E acc ). While improved gradient is at the forefront for certain machines (ILC), improved quality factor has broader impact, benefitting all SRF applications. An important opportunity for accelerator science and technology to move forward arose in the course of building the LCLS-II, the second generation Linac Coherent Light Source at SLAC. At more or less the same time, researchers at Fermilab discovered that introducing a small amount of nitrogen to the niobium surface could improve the mid-range quality factor as much as three-fold. A firm resolution of how nitrogen confers its benefit attracts much current research interest. The key elements of the “nitrogen doping” process were vacuum bake at 800 °C, brief exposure to mTorr of nitrogen at several hundred degrees followed by electropolish (EP) to remove several microns from the surface to eliminate unwanted nitrides: While the process as a whole was novel, the comprising unit operations are familiar to the accelerator community. It was judged reasonable to adopt it as a cost-reduction technology for LCLS-II. Researchers carried out a program of varying process parameters and measuring performance in single-cell cavities, leading to a consensus stable protocol for the project. The transition to vendor fabrication and multiple niobium sources has presented unforeseen challenges of performance variation evidently not connected to anything that could be incorporated in a purchase specification. Moving beyond the high temperature N-doping process above, researchers reported a simplified process consisting entirely of tens of hours anneal in a N atmosphere at low temperatures (~120°C – 160°C) after 800 °C UHV bake. These processes typically yield a few-nm doped layer while the high temperature process yields at least a few to many micron doped layer. Even more recently, oxygen has been used to dope instead of nitrogen which leaves a few-µm O-alloyed layer upon vacuum annealing for 300 °C for ~3 hours. The investigation of these materials is just beginning, but the process simplification they may offer is surely attractive. The very low quantity of material that appears to be significant in the “infusion” process indicates the need for very careful control of gas species available for diffusion into the surface during low temperature treatment, both for process control and research to characterize the underlying dynamics. Oxygen alloying offers the further opportunity to utilize the decomposition of the surface native oxide as the dopant source. It is necessary to understand and (thus) manage this process. We have been supported by the Department of Energy Offices of High Energy Physics and Nuclear Physics to pursue this goal.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Pattern-matching indexing of Laue and monochromatic serial crystallography data for applications in materials science

Serial crystallography data can be challenging to index, as each frame is processed individually, rather than being processed as a whole like in conventional X-ray single-crystal crystallography. An algorithm has been developed to index still diffraction patterns arising from small-unit-cell samples. The algorithm is based on the matching of reciprocal-lattice vector pairs, as developed for Laue microdiffraction data indexing, combined with three-dimensional pattern matching using a nearest-neighbors approach. As a result, large-bandpass data (e.g. 5–24 keV energy range) and monochromatic data can be processed, the main requirement being prior knowledge of the unit cell. Furthermore, angles calculated in the vicinity of a few theoretical and experimental reciprocal-lattice vectors are compared, and only vectors with the highest number of common angles are selected as candidates to obtain the orientation matrix. Global matching on the entire pattern is then checked. Four indexing options are available, two for the ranking of the theoretical reciprocal-lattice vectors and two for reducing the number of possible candidates. Furthermore, the algorithm has been used to index several data sets collected under different experimental conditions on a series of model samples. Additionally, knowing the crystallographic structure of the sample and using this information to rank the theoretical reflections based on the structure factors helps the indexing of large-bandpass data for the largest-unit-cell samples. For small-bandpass data, shortening the candidate list to determine the orientation matrix should be based on matching pairs of reciprocal-lattice vectors instead of triplet matching.

36 MATERIALS SCIENCE↗
NASA NTRS1992

Research experiences on materials science in space aboard Salyut and Mir

From 1980 through 1991 approximately 500 materials processing experiments were performed aboard the space stations Salyut 6, Salyut 7 and Mir. This includes work on catalysts, polymers, metals and alloys, optical materials, superconductors, electronic crystals, thin film semiconductors, super ionic crystals, ceramics, and protein crystals. Often the resulting materials were surprisingly superior to those prepared on earth. The Soviets were the first to fabricate a laser (CdS) from a crystal grown in space, the first to grow a heterostructure in space, the first super ionic crystal in space, the first crystals of CdTe and its alloys, the first zeolite crystals, the first protein crystals, the first chromium disilicide glass, etc. The results were used to optimize terrestrial materials processing operations in Soviet industry. The characteristics of these three space stations are reviewed, along with the advantages of a space station for materials research, and the problems encountered by the materials scientists who used them. For example, the stations and the materials processing equipment were designed without significant input from the scientific community that would be using them. It is pointed out that successful results have been achieved also by materials processing at high gravity in large centrifuges. This research is also continuing around the world, including at Clarkson University. It is recommended that experiments be conducted in centrifuges in space, in order to investigate the acceleration regime between earth's gravity and the microgravity achieved in orbiting space stations. One cannot expect to understand the influence of gravity on materials processing from only two data points, earth's gravity and microgravity. One must also understand the influence of fluctuations in acceleration on board space stations, the so-called 'g-jitter.' This paper is presented in outline and graphical form.

Regel, Liya L.↗
NASA NTRS1986

Materials sciences in space

A summary is presented of recent theoretical and experimental examinations of materials processing methods in microgravity conditions. The discussion covers Skylab and Spacelab flights, rocket and parabolic flights, and drop tube experiments. Attention is given to crystal growth, fluid physics, metallurgical and electrophoresis experiments.

Feuerbacher, B.↗
NASA NTRS1992

Five experiments in materials science for less than $10.00

Diffusion, twinning, fatigue, acoustic emission, and aging can be studied using readily available materials and the household oven. Each experiment can be expanded to a more extensive investigation of the properties of the material investigated, as well as other materials, and offers an opportunity for the student to learn about the relationship between engineering, science, society, and politics.

Spiegel, F. Xavier↗
NASA NTRS1993

Experiments in materials science from household items

Everyday household items are used to demonstrate some unique properties of materials. A coat hanger, rubber band, balloon, and corn starch have typical properties which we often take for granted but can be truly amazing.

Spiegel, F. Xavier↗
NASA NTRS1976

Review of NASA activities in materials sciences in space

In the year since the 18th Plenary Meeting of COSPAR, NASA has conducted eight materials processing experiments on the Apollo-Soyuz mission and 17 on two rocket flights. In addition, these three missions have implemented one Soviet and three German experiments. The Apollo-Soyuz results have confirmed and extended the findings of the Skylab experiments on solidification and crystal growth effects and have also established capabilities for separating living cells by electrophoresis and returning them still living to earth. The rocket missions provide repetitive flight opportunities much as the Space Shuttle will do, and they are being used to develop research approaches in which investigators will undertake projects calling for multiple space experiments rather than proposing experiments individually. During the year, NASA has also completed definition work on the major payload facilities planned for its initial materials processing experiment program on the Space Shuttle and Spacelab missions of 1980-81.

Bredt, J. H.↗