2022 CMSC

ABSTRACT

Electrochemical Pathways Towards Deep Decarbonization and Profitable Sustainability

A sustainable future is axiomatically a carbon-free electric future. Emerging technologies that will usher in this new economy necessarily include electrochemical innovations in energy storage and in steelmaking. Electricity storage is critical to widespread deployment of carbon-free but intermittent renewables, solar and wind, while offering huge benefits to today’s grid: improving security and reducing price volatility. Invented at MIT, the liquid metal battery provides colossal power capability on demand and long service lifetime at very low cost and without threat of fire. In 2019 worldwide steel production generated 9% of total CO2 emissions. Invented at MIT, molten oxide electrolysis represents an environmentally sound alternative to today’s carbon-intensive thermochemical process. Instead of CO2 as the by-product of steel, molten oxide electrolysis makes tonnage oxygen while offering better metal at lower cost while vitiating negative environmental impacts of current technology. In the narratives of both of these emerging technologies, liquid metal battery and molten oxide electrolysis, there are lessons more broadly applicable to innovation: how to pose the right question, how to engage young minds (not experts), establishing a creative culture, and inventing inventors in parallel with inventing technology.

BIOGRAPHY

Donald Robert Sadoway is a Professor of Materials Chemistry at the Massachusetts Institute of Technology. Sadoway was born in Toronto, Ontario, Canada. He did both his undergraduate and graduate studies at the University of Toronto, receiving his PhD in 1977.

A faculty member in the Department of Materials Science Engineering, he is a noted expert on batteries and has done significant research on how to improve the performance and longevity of portable power sources. In parallel, he is an expert on the extraction of metals from their ores and the inventor of molten oxide electrolysis, which has the potential to produce crude steel without the use of carbon reductant thereby totally eliminating greenhouse gas emissions.

Professor Sadoway’s research seeks to establish the scientific underpinnings for technologies that make efficient use of energy and natural resources in an environmentally sound manner. This spans engineering applications and the supportive fundamental science. The overarching theme of his work is electrochemistry in nonaqueous media.

ABSTRACT

Towards Managing Advanced Steel Surface Chemistries in Continuous Annealing and Galvanizing

The world-wide cost of corrosion estimated at approximately $2.5 trillion USD per year, a significant portion of which can be assigned to the corrosion of ferrous materials. This cost is significantly mitigated, however, through galvanizing, in which a thin layer of Zn applied to the steel surface such that it sacrificially protects the underlying steel from aqueous corrosion. Globally, almost 350 Mt/year of sheet steel are galvanized, making it one of the most important technologies deployed to manage the costs of corrosion. In addition, the extension of product and infrastructure lifetimes provided by the corrosion prevention of steel through galvanizing has kept millions of tons of carbon dioxide from being emitted in replacement steel production.

More recently, significant vehicle mass reductions have been realized through the increased deployment of Zn-coated advanced high strength steels (AHSSs) in advanced automotive architectures. This dramatic change has led to significant safety and fuel efficiency improvements in conventional vehicles and is a key enabler to the deployment of the next generation of electric vehicles. Increases in AHSS properties have typically come through more highly alloyed steel chemistries coupled with sophisticated thermal processing routes and part geometries employing thinner material cross-sections – for which robust corrosion protection provided through galvanizing is essential to maintain vehicle safety.

However, the increased levels of alloying elements have resulted in complex surface chemistries and significant challenges with respect to the production of high-quality Zn-based coatings. This paper will discuss the fundamental challenges of deploying Zn-coated advanced steels into automotive structures, with a focus on gas/metal reaction thermodynamics and kinetics, the resultant surface chemistries and how these can be beneficially altered through various processing strategies ensuring that the required reactions with the zinc alloy bath take place.

BIOGRAPHY

Professor Joe McDermid earned his bachelor’s degree in Metallurgical and Materials Engineering at Queen’s University in 1985 and his Ph.D. in Metallurgical Engineering from Mcgill University in 1992. Joe McDermid is presently Professor at McMaster University, in the Department of Materials Science and Engineering. He has been working at McMaster for over 16 years. He previously worked at Noranda Technology Centre from 1992-2003 as a Senior Scientist.

As the NSERC/Stelco Industrial Research Chair in Advanced Coated Steels from 2003 to present, McDermid has focused on integrating and developing new grades of advanced high strength steels for automotive weight reduction and safety enhancement with the continuous galvanizing process, the most widely practiced and cost-effective means of protecting steels against corrosion.

His expertise is in Physical Metallurgy of Advanced High Strength Steels, Microstructure-Property Relationships, High-Temperature Oxidation, Continuous Galvanizing of Advanced Steels, Reactive Wetting, Electron Microscopy.

Prof. McDermid was Editor-in-Chief of the Canadian Metallurgical Quarterly from 2013 to 2021. During his term, he increased the Impact Factor of the journal from 0.6 to above 1.2. He also contributed to several special edition volumes of the Canadian Metallurgical Quarterly.

ABSTRACT

Atomistic processes of deformation in nanocrystals with in-situ high resolution transmission electron microscope

Competition between different deformation mechanisms in nanoscale materials determines their plastic behaviours. Here, by in-situ high resolution transmission electron microscopy (HRTEM) observation, the competition of interior deformation mechanisms in nanocrystals were revealed. It was found the competition between the emission of leading partials and trailing partials from surface led to the transition between dislocation slip and twinning in gold nanocrystals. The orientation-dependent plasticity was also observed in body-centered cubic tungsten nanowires. Twinning-dominated plastic behaviour and discrete shear-band plasticity in tungsten nanowires were found, which was contributed to the competition between twinning and dislocation-slip under different loading orientation. In addition, an interesting deformation model, diffusional creep, different with the dislocation-slip and twinning, was demonstrated to play an important role on the plasticity in nanowires at room temperature. The surface-creep activated by dislocation-slip could lead to a super-elongation in silver nanocrystals with certain range sample diameters while the dislocation slip would dominate the deformation beyond the range. These works advance understanding of the competition and transition among dislocation slip, twinning and surface diffusional creep, which provides guidelines to optimize the mechanical performances of metallic nanocrystals in application.

BIOGRAPHY

Dr. Scott X Mao was the John Swanson Endowed Professor in the Department of Mechanical Engineering and Materials Science at the University of Pittsburgh. He obtained his Ph.D. in Tohuku University in 1988., worked at M.I.T. and Harvard University as post-doc and visiting faculty, and faculty at University of Calgary between 1989-1998. His research interests focus on microstructure relationship with mechanical behavior of metallic materials with in-situ transmission electron microscopy (TEM).

Dr. Mao made contributions in the research on deformation physics of metals and a pioneer in atomic scale in-situ TEM with over 300 publications including 235 journal papers with over 20 Science, Nature and Nature-serials articles, has achieved international reputation in in-situ transmission electron microscope. He has given over one hundred keynote, plenary and invited talks in national/international conferences and symposiums, and serves as Editor in-Chef, and Honorary Editor-in-Chief for International Journal of Metallurgy and Metal Physics, and Advanced Materials Science and Technology respectively. He has been honored by distinguished awards at his home institution and internationally, such as Elected Fellow of Canadian Academy of Engineering, Elected APS fellow (American Physics Society), Elected Fellow of IAAM (International Association of Advanced Materials, Sweden), ASME fellow, Vebleo Fellow, the Chancellor’s Distinguished Research Award, Esso Research Excellence Award, the William Kepler Whiteford Endowed and the John Swanson Endowed Professor. He was past chairs for TMS (Metals, Materials & Minerals Society) Committee on Mechanical Behaviour of Materials, IMS (International Metallographic Society) finance committee, Guest-editor for Material Science & Engineering International Journal, and Editorial Board member for Nanomaterials, Acta Metallurgica Sinica, and Journal of Nanotechnology and Nanomaterials.