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Materials Science and Engineering
INTRODUCTION
Within the Materials Science and Engineering Division (MSED), there are a total of 194 staff members, which includes permanent staff, postdoctoral fellows, associates, and administrative support. In 2014, the staff was 182, and so the total staff count has grown by 12 over the past 3 years. The MSED staff represents about 19 percent of the total MML staff. The budget for 2017 is $27.3 million, and this includes indirect costs.
The MSED covers a broad range of activities in five research areas: additive manufacturing, dynamic measurements for materials manufacturing, the Materials Genome Initiative (MGI), the foundry for functional materials measurement, and infrastructure renewal. The MSED made six presentations during the review, which focused on the Polymer Processing Group, the Thermodynamics and Kinetics Group, the Mechanical Performance Group, the Polymer and Complex Fluids Group, the Functional Polymers Group, and the Functional Nanostructured Materials Group.
ASSESSMENT OF TECHNICAL PROGRAMS
Accomplishments
The Thermodynamics and Kinetics Group consists of 12 permanent staff and 11 research associates. The group is to be commended for its excellent progress since the last review. It is highly competent and working well together. Its engagement in the Center for Hierarchical Materials Design (CHiMaD) program with Northwestern University and the University of Chicago appears to be very strong. The group has made many computational tools and software available to a diverse range of users. The group is involved in computational materials science from the atomistic level to the continuum level—often bridging scales. Its ability to bridge scales is important because it enables the group to compare theoretical predictions with experimental results. The quality of computational materials science, particularly in Computer Coupling of Phase Diagrams and Thermochemistry (CALPHAD), density functional theory (DFT), multicomponent diffusion, atomistics, and phase field, are among the best in the world in computational modeling and alloy development in metals. These tools are branching out into, and complementing, computational tools in soft materials. An example of this core competency is validated by the National Institute of Standards and Technology (NIST) leadership role in the MGI, where for example, the objective of the Thermodynamics and Kinetics Group is to develop materials informatics and computation tools to advance the initiative, with accomplishments such as the Customized DSpace, Interatomic Potential Repository, JARVIS-FF, and JARVIC-DFT to name a few. The materials design toolkit is providing value for the entire computational materials community.
The group is also studying some very complex problems such as multicomponent alloys systems. It is predicting properties and experimentally verifying them. An example is the Al-Co-W system. The prediction of the diffusion coefficient and its verification by experiments is an important accomplishment.
Also, its studies on changes in material structure after thermal treatment following additive manufacturing of IN625 alloy is a good accomplishment. Design of Cu-Ni-Zn alloy as a replacement for nickel (requested by the U.S. Mint) is an excellent example of materials design and experimental demonstration. This switch to an alloy is expected to significantly lower the cost of a nickel.
The Mechanical Performance Group demonstrates best-in-the-world work on highly quantified mechanical performance in multiaxial stress state applications. The cruciform tester has high industrial relevance for fabrication and end product reliability and safety. It would be good to evaluate the mechanical performance capability at the NIST Boulder, Colorado, facility for a complete perspective of testing capability. One indicator of best-in-the-world human resource expertise is that the group has been asked to give its consultation on national-level failure analysis issues such as the World Trade Center collapse.
Automotive lightweighting is highly important to our nations’ energy use profile and global CO2 reduction goals. The cruciform testing work being performed at the MSED directly impacts the lightweighting of automotive body closure sheet. An example is Ford’s F-150 lightweighting efforts as well as General Motors’s (GM’s) steel lightweighting efforts. There were strong signs of the group’s industrial engagement as evidenced by interaction with Ford Motor Company on C-fiber and GM on ultra-high-strength steel sheet for transportation lightweighting. There was also clear evidence of an open source focus of tools, such as Python, which aids adoption by the technical community. Two notable, innovative projects that are drawing closer to completion are coinage (patents pending) and co-based super alloy development, which is essential to jet engine fuel efficiency.
Collaboration with six other organizations on additive manufacturing, with respect to the role of accurate measurements in this highly active field, demonstrates the philosophy of providing value and not just researching in a hot field. This is a clear niche where NIST brings value to the additive manufacturing community. The NIST-founded Additive Manufacturing Benchmark Test Series (AM Bench) and its depth of expertise in physical metallurgy are other areas that differentiate NIST from other laboratories in additive manufacturing.
Substantial leadership on the American Society for Testing and Materials (ASTM) and other standards committees is viewed by industrial reviewers as highly advantageous. NIST staff members are unbiased and provide sound perspectives, particularly when committees are composed of other members, such as suppliers and users of materials that can financially benefit from specific wording within specifications.
The Functional Nanostructured Materials Group is to be commended for its excellent progress. Extreme bottom-up superfilling is a high-visibility contribution, which has been carried out over more than a decade. It is used by industry to guide the development of advanced superfilling systems of different geometry and materials, and offers an opportunity to focus more on scientific mechanisms. Self-termination electrodeposition used to deposit mixed-metal thin catalytic films with superior catalytic properties is another example of a notable achievement.
The group is conducting work on electrochemical microscopy, which is an established method. However, the group is using it in a novel way. Still, it would be useful to highlight how this differs from traditional electrochemical microscopy. In situ stress measurements such as short-term and long-term stable methods are valuable. Linking to wider applications would require collaborative interactions to build on NIST’s fundamental scientific accomplishments.
The group’s research on the electrocatalysis of formic acid oxidation to produce CO2 formation without CO poisoning is an advance that builds on in situ experiment and theory. The group also maintains a close connection between modeling and surface analysis. The transmission electron microscopy (TEM) tracking of the Li-ion battery and moving to DYNAMIC observations are good examples of its other accomplishments.
Accomplishments within the Polymer Processing Group, the Polymers and Complex Fluids Group, and the Functional Polymers Group are discussed later. These include the synthesis of near-perfect short branch spacing polyethylenes (which may become the basis for some new and needed polyolefin standard reference materials [SRMs]) and the synthesis of model networks using cyclic polymers that produce
cross-linked networks with no dangling ends. Other examples of significant accomplishments include the control of surface exchange between a surfactant and DNA; the NIST on a chip initiative using holography in collaboration with CHiMaD; the development of the ZENO tools for the calculation of several polymer properties (some aspects have very recently become publicly available); a new approach to course graining of polymer dynamics, the use of quasi-elastic neutron scattering to quantify electrolyte dynamics in solid polymer electrolytes; and the use of fluorescence probes to locate water invasion into composite materials.
Four projects within the MSED—the additive manufacturing of metals, mechanical standards, performance under extreme conditions, and automotive lightweighting—are highly pertinent to achieving national goals throughout the materials innovation continuum. The MSED’s leadership in the digital image correlation for strain measurement is also establishing needed best practices worldwide. The scientific expertise necessary to achieve technical goals and make major advances is excellent. Additionally, computational modeling and characterization of materials within the MSED is clearly among the best in the world, and there is substantial value in both validating and balancing computational modeling with experiments. NIST could foreseeably reestablish its role as the leader among government agencies.
The strategic planning process as well as the first strategic plan are viewed as a positive experience by the MSED. There are additional questions concerning the level of individual and group training in the tactical implementation of plans, as well as the facilitation of this process. It appears, however, that the group is now learning how to best develop and implement tactical plans that flow from the strategic plan. Strategic and tactical planning takes years to internalize into an organization and this is a positive start.
The researchers within the MSED also articulated that bringing technical value and being wise about spending taxpayer dollars is a key concept that drives many of their program (and equipment) decisions. These decisions include crosscutting collaboration between groups and other branches of government; scientific and technical recognition; a learning environment; an angel investing program; science, technology, engineering, and mathematics (STEM) participation with local high schools and community colleges; and alternative career path options; among others.
Opportunities and Challenges
Opportunities to improve technical programs within the MSED include conducting more experimental work in conjunction with modeling to verify predictions across a number of systems. This may be better achieved by using model systems, which are easier to model with computational methods, and also may be easier to fabricate experimentally. The current focus seems to be on rather complex systems. The complex nature of these materials may make it difficult to truly design materials from the ground up, especially when the processing conditions are far from thermodynamic equilibrium. Under such circumstances, researchers may need to use multiple fitting parameters to compare with the experimental results. If the actual processing is under conditions far from thermodynamic equilibrium, the use of kinetic and transport parameters would be needed to achieve congruence between theory and experiments.
The work on magnetic nanoparticles is excellent. There is a potential opportunity to apply this research in the field of medicine. The group may want to consider linking to medical community users and researchers, both within and outside of NIST.
There is worldwide activity in magnetic materials, energy storage, nanowires, and Li-ion research. Given the limited manpower and resources, it would be useful to reevaluate where the MSED can make unique contributions to such activities to ensure that it is not spreading itself too thin.
The modeling capabilities within the MSED are good. One opportunity could be to make modeling superfill codes reusable by others, so that they could both be useful to investigate different mechanisms, and to compare with modeling. Additionally, the field of electrochemistry has an enormous physical
property database that could be utilized by NIST. For example, there is a property database on molten salts.
There is also an opportunity to work with the MGI to participate in the discovery of new electrocatalysts and other materials with potentially unique properties.
Also, given the limited manpower and resources, it would useful to reevaluate the balance between long-term goals and short-term projects approaching maturity.
Routine methods are available for tracking error bars in experimental and computational studies. Their use is encouraged for uncertainty quantification when data and numerical results are combined in composing predictions for more complex systems. Tracking error sources and modeling uncertainty can assist in helping researchers decide where to invest their energies, in order to make improvements (i.e., more experimental data, improved assumptions, empirical corrections that reduce methodological errors, or better management of basis set truncation errors) in a complex system.
While there is considerable expertise in electrochemistry and engineering processing at NIST, it seems to be dispersed among other programs. Synergies might be possible for building new research directions. Examples include the pH measurements conducted and collaboration with the Marine Biochemical Sciences Group. Other examples include exploring the use of solid electrolytes in chemical science for nuclear chemistry. Collaborations can be envisioned with the Functional Polymers Group for work on various transport membranes.
New initiatives from bottom-up ideas can help to maintain a dynamic balance as top-down projects mature. Small projects can help to sustain technical programs, as their objectives are achieved, and new directions present themselves.
Finally, in future reviews, the use of poster sessions would provide direct contact between staff and reviewers. Such activities are useful for assessing the depth of expertise brought to bear on projects, and also for assessing the knowledge of whom else in the field, past and present, is highly regarded.
PORTFOLIO OF SCIENTIFIC EXPERTISE
Accomplishments
There is a very good mix of theorists and experimentalists within the MSED. Many of the scientific staff and postdoctoral fellows have strong backgrounds in fundamental sciences and engineering. Several have degrees in physics, applied physics, chemical engineering, and materials science and engineering. Postdoctoral fellows and staff have opportunities to attend professional meetings, present their work, and gain exposure to the work of other researchers. This also helps them to grow professionally, as well as make changes in their career paths—for example, some have recently joined academia.
Many MSED researchers have excellent citations to their published work, which shows that their work is recognized by the scientific community at large. It was noted that there are at least five researchers with over 4000 citations. Many have received prestigious NIST internal awards (bronze and silver medals).
One example of organizational expertise concerning human resource issues was the hiring of bachelor of science-level and master of science-level engineers into technician roles to improve productivity. This close partnering of senior researchers with technicians has been very fruitful for improving testing throughput and improving the quality of the output of the tests themselves in a very cost effective manner. This organizational model may have utility in other groups.
There has been an expansion from a pure science focus toward an engineering focus that provides additional short-term and long-term value for the United States. It is important to note that the quality of pure science did not suffer from this expansion of focus into engineering, which is a testament to the collective openness of the members of the MSED. There exists a positive employee culture within the MSED. There are many components to job satisfaction, and there is extensive management thought and action given to nonfinancial factors that impact job satisfaction.
Opportunities and Challenges
The scientific staff within the MSED is first rate. Many have received internal awards and recognitions. It is important that the MSED management put a structure in place that will, on a regular basis, nominate scientific staff for external awards—such as awards from professional societies. Many societies have junior-level awards, and several also have high-profile external awards (e.g., the American Physical Society [APS] Fellowship; the American Chemical Society [ACS] Fellowship; The Minerals, Metals, and Materials Society [TMS] William Home-Rothery Award and Brimacombe Medal; and the American Society of Materials [ASM] Gibbs Award). Enacting such a structure needs to be made a priority.
One of the challenges is how to utilize postdoctoral fellows more effectively in ways that will help both them and also the institute. There was a concern that postdoctoral fellows have to spend a lot of time learning equipment maintenance and troubleshooting. They are not experienced in this, and are typically only in their positions for a couple of years. This can potentially lead to inefficient use of the postdoctoral fellows, and may also impede their progress toward career goals in research. It may be better to hire some engineer-level permanent staff to maintain the equipment. This may actually lead to increased research productivity, which is already very good. Additionally, staffing for the facilities would benefit from training, technical maintenance, and modernization.
There is high reliance on postdoctoral candidates for succession planning of top-level researchers. And so, succession planning opportunities exist within the MSED.
Linking with the Boulder Statistics Group may be beneficial, since that group reviews the literature, and evaluates and sells data. It also scans publications to assess the quality of the data and stores this data. NIST’s Joint Army Navy Airforce (JANAF) Thermochemical Tables are valuable collective data compilations.
Last, the MSED also needs to look across other programs to develop a collaborative effort and utilize available expertise.
ADEQUACY OF FACILITIES, EQUIPMENT, AND HUMAN RESOURCES
Accomplishments
Despite difficulties related to old buildings and infrastructure (e.g., the facility used to perform high-strain-rate testing, which had issues with a leaking roof), the staff has done an excellent job of maintaining equipment in working order. It has also improvised equipment for its specific needs. Some of the facility is rather old, but it is still functional. The facility also includes state-of-the-art electron microscopy. The Split Hopkinson Bar (for both tension and compression) is a state-of-the-art instrument, which also has fast recording capability (an infrared camera) for temperature measurements during rapid loading. Its Advanced Photon Source facility as well as its specialized mechanical testing of automotive parts is unique. This facility also has the ability to use X-ray beams directed at the center of a metal plate that is being deformed. This is particularly important to the automotive industry. Additionally, a liquid metal source X-ray instrument that uses liquid Ga-In alloy is among the key instrumentation within the MSED. There has also been great collaboration on X-ray synchrotron beam line use at different government facilities, primarily in the Department of Energy (DOE).
State-of-the-art instrumentation developments within the polymer-side of MSED include the resonant soft X-ray small angle scattering instrument; the modified MakerBot 3D printer; a novel three-in-one instrument that allows for correlations of polymer rheology with underlying microstructure and composition; an automated multifiber fragmentation machine; a microcapillary rheometer; and a layer-by-layer method for the highly controlled fabrication of model membranes for water purification.
In terms of human resources, the administrative support within the MSED consists of at least three highly experienced employees with 27 years of experience.
Opportunities and Challenges
Aging structures and leaking roofs in some of the facilities is a major issue. Some strategic planning may be necessary to address these continuing issues. Building facilities need improvement in order to both improve safety and protect valuable equipment. Researchers have taken steps to do this by building metal shelters within rooms to protect equipment and experiments from rainwater damage and drastic humidity excursions during rain events. The issue of facility infrastructure is a challenging topic in buildings that are over 50 years old and during time periods of constrained budgets.
Additionally, the equipment for the empirical synthesis of materials is substantially less than best in the world. It would be advantageous to upgrade experimental (fabrication) capability and metallographic capability to match the MSED’s computational and more advanced characterization capabilities. Last, the process of acquiring laboratory and computer equipment is still a challenge since the 2014 National Academies Assessment.
DISSEMINATION OF OUTPUTS
Accomplishments
The MSED staff members have been active in publishing in peer-reviewed high-impact journals. Based on the number of papers, and their publications in these journals, it is clear that the research work is being disseminated in an effective way. They are publishing in journals such as the Journal of the American Chemical Society, Advanced Energy Materials, Nature-Scientific Reports, Advanced Materials, Physical Review Letters, ACS Nano, and Langmuir. The Functional Nanostructured Materials Group has 81 reviewed research publications—which is an outstanding record of public dissemination of scientific results. In the polymers research focus, 27 permanent MSED staff produced approximately 240 publications in peer-reviewed journals and conducted 300 invited talks. This excellent productivity has been greatly enhanced by the presence of the National Research Council (NRC) postdoctoral fellows and research associates from all over the world. The Functional Polymers Group, the Polymers and Complex Fluids Group, and the Polymers Processing Group appear to be on the cutting edge in several technological areas and are best in the world in some. They have been able to maintain the excellent reputation of NIST in polymer science and engineering.
Other MSED dissemination activities include making and supplying standard materials, work delivered through Cooperative Research and Development Agreements (CRADAs), and achieving several external and internal recognitions. MSED leadership is very active in external organizations. Collaboration with the University of Chicago through CHiMaD seems to be going very well in several projects. There continues to be an excellent interaction of theory and modeling efforts with experiments. The MSED’s contact and interaction with industrial and academic partners is also excellent. Active participation as leaders in standards organizations and specialized conferences has been especially notable and needs to be continued and encouraged.
There has also been substantial progress since the 2014 National Academies Assessment on improving external attendance at national and international conferences from both a financial and an administrative approval process perspective.
Opportunities and Challenges
It would be useful to link with other electrochemical activities on other project teams. It would also be useful to utilize the postdoctoral network within NIST to identify linkages. There also appear to be opportunities to collaborate across many areas within the MSED, the MML, and other parts of NIST.
The quality of work within the MSED appears to be very good; however, during the review no information was given in some of the presentations and talks (e.g., the Thermodynamics and Kinetics Group’s presentation) on how many papers were published, patents applied for, and presentations given at professional society meetings. A publications list was received upon request. Additionally, the presentations did not have citations to similar work (at other places). This makes it difficult to put the uniqueness of the MSED work in the correct context. It is important that citations to other work outside of NIST be included in the slides, as this omission was across the board.
Additionally, one of the main missions of NIST is to collaborate with outside researchers. The unique facilities and the expertise of NIST researchers are a clear draw and benefit for others. This leads to many collaborative papers. It is recommended that for the next National Academies Assessment, the published papers be listed in three categories: (1) papers solely authored by NIST researchers; (2) collaborative papers with outside researchers where the NIST researchers are major contributors; and (3) collaborative papers where NIST researchers have a supporting role. Such an approach will allow proper attribution representing the various roles that NIST plays in advancing the nation’s science and technology.
