The Northern California Section serves ACerS members who reside or work in the following counties of California: Alameda, Amador, Calaveras, Contra Costa, El Dorado, Madera, Marin, Mariposa, Merced, Monterey, Napa, Sacramento, San Benito, San Francisco, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Solano, Sonoma, Stanislaus, Sutter, Tuolumne, and Yolo.
Chair: Scott McCormack, University of California, Davis
Funding Secretary: Andy Nieto, Naval Postgraduate School
Recruitment Secretary: Adrian Radocea
Events Secretary: Samuel Zhu
Treasurer: Jenny Beach, Exponent
If you would like to contact any of the Northern California Section officers, visit the ACerS online membership directory for contact details. You must be a member to access the directory. Or contact Karen McCurdy at firstname.lastname@example.org for assistance.
Meetings and Activities
Section Chair Scott McCormack participates in new Ceramic Tech Chat episode!
Hosted by ACerS Bulletin editors, Ceramic Tech Chat talks with ACerS members to learn about their unique and personal stories of how they found their way to careers in ceramics.
Finding the way that you learn best can help you to achieve goals that may once have seemed out of reach. In this thirteenth episode, Scott McCormack, assistant professor of materials science and engineering at the University of California, Davis, discusses how he overcame learning challenges during his elementary school years, how he helps his own students learn the sometimes scary topic of thermodynamics, and his experience setting up a university research program as a young professor.
ACerS Northern California pilots Young Professional Series
The Northern California Section of ACerS is continuing its weekly Young Professionals Seminar series. The series has been designed to showcase the work of academic and industrial young professionals to the Northern California community.
Presentations are virtual with 30 minutes of content and 15 minutes of questions and answers. No registration is required. Join the presentations via this Zoom link, Meeting ID: 992 4523 3313, Passcode: 802011.
Contact Scott McCormack for more information.
Schedule of Presentations:
High-entropy ceramics have potential to improve the mechanical properties and high-temperature stability over traditional ceramics, and high entropy nitrides and carbonitrides (HENs and HECNs) are particularly attractive for high temperature and high hardness applications. In this talk, the synthesis of 11 bulk HENs and HECNs forming single-phase materials with high hardness will be discussed. The enhancement in mechanical properties is tied to configurational entropy and valence electron concentration, providing opportunities for tuning mechanical properties of high-entropy ceramics. A novel entropy metric for the determination of "high-entropy" classification in complex crystal structures will also be discussed.
Olivia is a PhD candidate at the University of California San Diego, working in Dr. Ken Vecchio's lab. She works on high-entropy ceramics as well as metal additive manufacturing projects. Prior to her PhD work, she had a Post-Baccalaureate position at Los Alamos National Laboratory and received her bachelor's degree from Carnegie Mellon University in Biomedical Engineering and Materials Science Engineering.
Jeroen Deijkers originally hails from The Netherlands, where he obtained a MS in Aerospace Engineering at Delft University of Technology and completed his Ph.D. in Materials Science & Engineering at the University of Virginia under the supervision of Prof. Haydn Wadley. He specializes in the design, synthesis, and process optimization, of novel high-temperature materials for use in the aero- and space-industry.
During his Ph.D., he investigated methods to reduce oxide (cristobalite) growth in silicon-Yb2Si2O7 EBC systems by addition of a thin HfO2 reaction layer between the silicon and Yb2Si2O7¬ layers, forming hafnon (HfSiO4) in the process. He also investigated the addition of a HfO2-based thermal barrier coating (TBC) to the Yb2Si2O7 layer in order to reduce temperature throughout the coating system and allow for design of better molten silicate resistance in engines. He currently is a Postdoctoral Research Associate in the Wadley group, continuing research into multi-functional barrier coatings for aero-engines.
"Multi-Component rare-earth disilicates: An approach to tunable properties of environmental barrier coatings." by Jeroen Deijkers
Thursday, May 13, 2021, 9:00-9:45 a.m. (PST)
Although Yb2Si2O7 has a fairly low thermal conductivity (~4.5 W m-1 K-1), reducing the thermal conductivity can result in further reduction of the temperature across the environmental barrier coating (EBC) layer, resulting in lower oxide growth rates at the silicon bond coat surface, and potentially mitigating the formation of a crystalline SiO2 TGO. By including RE-cations of different sizes with the Yb2Si2O7 coating, phonon scattering can be increased and interrupt thermal mobility. While doing so it is important to maintain a CTE similar to that of the thick substrate in order to avoid coating failure.
An exploratory study was done where three binary systems were chosen in order to explore the design space across the RE-disilicate design spectrum, ranging from the smaller RE-cation-based Y2Si2O7, the medium-sized Gd2Si2O7, to the large RE-cation-based La2Si¬2O7. The composition space in these binaries varied from 100% Yb2Si2O7 to 100% of the alternate RE-disilicate in order to investigate the influence of mixing on the thermal conductivity and thermal expansion coefficient of binary RE-disilicate systems. A follow-up study was done to investigate the effect of mixing equimolar 2-, 3-, 4-, and 5- component powder mixtures, consisting of at least Yb2Si2O7, and either Y2Si2O7¬, Gd2Si2O7, or La2Si2O7, where other rare-earth (Y-, Lu-, or Er-based) disilicates were added to. The phase composition, thermal conductivity, and thermal expansion coefficient of the mixtures was found and compared to the individual and binary rare earth disilicates. Several single-phase mixtures with a CTE in the 4-5.5x10-6 °C-1 range and 1-2 W m-1 K-1 were identified and can be used as potential candidates for use as an EBC layer instead of YbDS.
"Oxidation of uranium and zirconium carbide" by Claudia Gasparrini
Thursday, May 20, 2021, 9- 9:45 a.m. (PST)
Zirconium carbide (ZrC) and uranium carbide (UC) are receiving attention as alternative materials to silicon carbide and uranium dioxide for nuclear fuel applications. However, when in contact with oxygen at relatively low partial pressure and low temperature they show poor oxidation resistance.
In situ techniques coupled with macro to nano characterisation techniques were used to reveal the oxidation mechanism of ZrC and UC. A key result was the improved understanding of the role of cracking in the oxidation mechanism of both carbides. Experiments on UC in air showed that oxidation proceeded quicker at lower temperatures, 873K, as oxide sintering at higher temperatures, 1173K, limited oxidation only on cracked surfaces.
The role of oxygen in ZrC stoichiometry has also been revaluated since C/Zr atomic ratio and ZrC lattice parameter were found to be heavily affected by its contamination.
Dr. Claudia Gasparrini is a EUROFusion Fellow at Consorzio RFX, Padua, Italy and an Academic Visitor in the Department of Materials at Imperial College London, London, U.K. She is currently working on water chemistry specification and corrosion mitigation strategies for the cooling water system of nuclear fusion reactors. She is passionate about the nuclear field and her research interests span from understanding nuclear fuels performance to irradiation damage on materials. In her PhD she investigated oxidation treatments of uranium carbide and zirconium carbide as a long-term storage solution for nuclear fuels. She graduated from Padua University, Italy with a MSc degree in Chemical Engineering after performing studies in Nuclear Engineering at the Royal Institute of Technology (KTH), Sweden.
"Entropy stabilized oxides" by Dr. Albert Voskanyan
Thursday, May 27, 2021, 9:00 a.m. to 9:45 a.m. (PST)
The entropic stabilization of energetically unfavorable materials has attracted immense attention and lead to the fabrication of new materials with distinctive physicochemical properties. We recently demonstrated that Wadsley-Roth crystallographic shear phases of the TiO2-Nb2O5 pseudobinary system such as TiNb2O7, TiNb5O14.5, and TiNb24O62 have endothermic enthalpies of formation from parent binary oxides (TiO2 and Nb2O5), implying that they are entropy stabilized and stable only above some critical temperature. The observed energetics suggest that TiNb24O62 has extensive cation disorder, whereas TiNb2O7 and TiNb5O14.5 appear to be substantially more ordered. Besides, we found that A6B2O17 (A = Zr, Hf; B = Nb, Ta) modulated structures are also entropy stabilized. The unfavorable energetics of formation is neutralized by large configurational entropy arising from cation disorder. The calculated configurational entropy per formula unit for A6B2O17 is around 3 times higher than the maximum configurational entropy value for an equimolar five cation containing “high entropy oxide” system. Our results demonstrate that entropy stabilization of these oxides is possible through the disorder of two cations rather than five or more cations. These phases and probably many others constitute a new and extensive class of entropy stabilized oxides or high-entropy oxides that are stable only at high temperature and in which positive enthalpies of formation are counterbalanced by large positive entropies arising from cation disorder.
Albert Voskanyan earned his PhD at the Department of Chemistry at the University of Hong Kong with a doctorate in Materials Science. His doctoral topic was to evaluate the impact of porosity in oxides at different length scales on the catalytic and electrochemical properties. He invented the colloidal solution combustion synthesis method which allows to produce oxide nanostructures with tailored porosity on a large scale in an energy efficient manner. Currently, he is a Postdoctoral Researcher at the Center for Materials of the Universe at Arizona State University and his research is focused on solid state chemistry and the investigation of the thermodynamic stability of multicomponent materials via high temperature oxide melt solution calorimetry. He has published around 20 papers in peer-reviewed journals, been a reviewer for different prestigious journals, and co-inventor of 2 US patents. In his free time, he loves to play chess and visit new places.
"Understanding reaction mechanisms in transition metal oxides", by Dr. Rebecca McAuliffe
June 3, 2021, 9:00 - 9:45 a.m. (PST)
Transition metal oxides are used for a wide range of applications and are synthesized through many different routes. Synthesis conditions are often chosen from literature or through intuition, but what effect do the synthesis conditions have on structure and properties of the resulting materials? By utilizing in situ X-ray and neutron diffraction, reactions can be observed and the underlying reaction mechanisms that guide a synthesis are revealed. In the case of synthesizing YMnOx via metathesis reactions, the choice of precursors plays a large role. Not only does the precursor compound matter, but the polymorph of the precursor determines the final structure of the YMnOx phase produced. This research provides an understanding of the reaction mechanisms in metathesis reactions and highlights the importance of using in situ techniques to better understand the reactions pathways that are present in the syntheses of complex transition metal oxides.
Rebecca McAuliffe is a postdoctoral fellow in the Energy Storage Group at Oak Ridge National Laboratory. She specializes in understanding the reaction mechanisms that guide the syntheses of energy materials using X-ray and neutron diffraction. Her research also focuses on developing tools to observe and model ion diffusion through interfaces using thin film heterostructures. Rebecca McAuliffe received her Ph.D. in Materials Science and Engineering from the University of Illinois at Urbana-Champaign.
ACerS President Dr. Dana Goski virtually visited the Northern California section and UC Davis MSE Department
The Northern California Section of ACerS welcomed ACerS President Dr. Dana Goski for two virtual events on February 23.
Dr. Goski and section members participated in a meet and greet discussion and exchanged ideas and plans for the Northern California Section.
Following the Section meet and greet, Dr. Goski's presented "Beyond Special Dirt", which was a personal perspective on the world of commercial refractories development: challenges, innovation and visioneering of these industrial materials.
Glass and Ceramics Arts Webinar hosted by Northern California Section
On December 8, ACerS Northern California Section continued to offer relevant programming with an interactive online showcase featuring Therese Lahaie, David Head and Smith Levi who shared their stories of art, glass and ceramics. The webinar can be viewed at this link.
As an artist, Therese has used light and technology to reveal the nature of glass as a medium for expressing solace as well as danger. Her glass research spans from the micro view, making photogram studies of life inside the bubbles, to the macro view, projecting video through architectural glass. She uses use glass as a reflective and refractive canvas with techniques of projecting, slumping, scouring, painting, polishing, printing, breaking, and motorizing it. Almost ten years ago, she returned from a trip to Dia Beacon, NY energized by the unexpected impact of scale in the minimalist sculpture installed there, and was driven to infuse her work with similar qualities. Ever since, she has been expanding her use of LED technology to construct light environments.
Therese Lahaie has sculptural work in the permanent collections of the Crocker Art Museum, California, Corning Museum of Glass Contemporary Collection, New York, the DiRosa Collection, California, and the Glassmuseet Ebeltoft, Denmark. She has been an artist in residence at the Kala Art Institute in California and had three honorary fellowships at the Djerassi Resident Artist Program in California.
Lahaie has a degree in glass sculpture from Massachusetts College of Art and a B.A. in Fine Art from Emmanuel College in Boston, MA. She is the 2015 award winner of the LuciteLux Just Imagine award for her public art project Crossing Signal Mosaic in Emeryville, CA.
She lives and works at the 45th Artist Cooperative in Emeryville, CA, where she is working on getting solar panels installed on the cooperatives live/work buildings.
David Head is a Certified Principal Engineer supporting optical hardware for flight and space applications at Lockheed Martin. He has over 30 years experience in a career which has spanned lasers, biomedical devices, injection molding, lenses and astronomical telescopes. Dave has over twenty patents and numerous publications.
Dave's time spent working with lasers gave him an appreciation for dielectric mirrors which he now incorporates into his sculptures. Work and training exposed him to tools and techniques for machining which he has evolved by building a small home shop. The combination of coated optics, metal working skills and a love of mobiles has fueled his artistic endeavors to create robust and beautiful kinetic works that are truly unique.
The discussion will briefly cover the optics of multilayer dielectric mirrors and how they are incorporated into kinetic sculptures. Dave will also show a novel design for a jeweled bearing used in one of his sculptures. Dave will show a number of sculptures that have been on display or presented in galleries. One of his works was on display in the skylight at the Nashville International Airport concourse.
Smith Levi Is a designer and metal fabricator currently working as lead shop technician for Glassybaby in Seattle, WA. Levi was immersed in the glass community from a young age as the child of glass artist, David Levi.
In 2012, Levi started working with metal building bicycle frames under the brand name RatKing Frames. Their interest in mechanical systems and fabrication has expanded into work in the hot shop.
In the past year, Levi has reimagined what glassblowing can be in the age of the Coronavirus by engineering pneumatic systems that remove the need for glassblowers to put their lips on a pipe. These pneumatic systems have been implemented as standard operating procedure for the Glassybaby factories and have afforded safe operation since their return to work in May 2020.
ACerS Webinar produced by the Northern California Section
On October 9, 2020, the Northern California Section of ACerS once again offered relevant programming with an interactive online showcase of start up companies actively using materials science to build innovative products. Three Bay Area (Silicon Valley) start up companies shared their stories of launching new companies and developing products. A link to the recording of the presentation can be found here.
Chris Eberspacher, Co-founder and Managing Director
Solar is the future of electricity. Consumers – residential, commercial and industrial – want cheap, reliable, preferably clean electrical power; and in many cases solar photovoltaics (PV) is the lowest-cost, most easily installed option. But traditional PV technology is approaching its efficiency limits, and traditional PV manufacturing is capital intensive. A new class of materials – metal-halide perovskites – provides a pathway to higher sunlight-to-electricity conversion efficiencies and lower scaling costs. Tandem PV is developing perovskite PV technology that can operate in tandem with traditional silicon PV to provide higher efficiencies, lower electricity costs and lower capacity scaling costs by leveraging rather than competing with the existing Si PV infrastructure.
Christine Ho, Co-founder and CEO
Printed, solid-state batteries are here now, making them the perfect fit for an expanding range of high-volume, ‘next-generation’ Internet of Things devices and applications. Thinness, flexibility, safety, disposability and customizability give product designers new freedom. This talk will showcase both the technology and cool applications like logistics smart tags and medical patches.
Nadir Bagaveyev, CEO and Chief Designer
Bagaveev Corporation is focused on the colonization of Earth's orbit with large habitats and scientific and commercial stations. The firm is currently working on designing and building a reusable single stage to orbit rocket. Bagaveev Corporation is studying into ceramics research as a way to create an ultralight reusable heat shield for orbital re-entry and is seeking partners in industry, government and academia to expedite R&D in high temperature materials, 3D printable and sprayable ceramics, transpiration and film cooling of ceramic surfaces.
The Northern California Section of ACerS held its inaugural event on July 14. Over 100 participants listened to three of the leaders in the lithium battery field present key information about the next generation lithium batteries. Topics discussed included advances in engineered cathode, anode and solid electrolyte materials for both lithium ion batteries and solid-state lithium batteries.
The webinar has been posted at this link.