Alec Balandin 

(Advisor: Prof. Josh Kacher] 

will propose a doctoral thesis entitled, 

PROCESSING, MICROSTRUCTURAL EVOLUTION, AND INTERFACIAL INTEGRITY OF HYDROGEN-REDUCED BIMETALLIC STRUCTURES

On

Monday, November 30

At

1:00 p.m.

In

J. Erskine Love Room 295

Abstract 

Hydrogen reduction of metal oxides offers a promising pathway toward carbon and energy efficient steel production, but the high cost of hydrogen and the complexity of conventional processing routes present challenges to widespread implementation. One potential approach is the development of extrusion-based near-net-shape manufacturing, in which metal oxide precursors are shaped into components prior to hydrogen reduction and sintering. This approach also enables the fabrication of bimetallic structures, combining dissimilar steel compositions to achieve properties that cannot be obtained from a single material. However, differences in reduction kinetics, sintering shrinkage, and thermal expansion between constituent materials can generate differential strains, residual stresses, and interfacial defects that compromise structural integrity. In this work, the fabrication of stainless steel 316/carbon steel bimetallic components through hydrogen reduction and sintering of extruded oxide mixtures is investigated. A central challenge is maintaining interfacial bonding and dimensional stability throughout processing, particularly as differences in reduction and densification behavior can lead to warping, porosity formation, and delamination. Preliminary results demonstrate the feasibility of producing bimetallic steel structures with distinct stainless steel and carbon steel regions, although localized interfacial delamination indicates that further control of processing conditions is necessary. This work aims to understand the relationships among reduction behavior, sintering shrinkage, interfacial microstructure, and thermomechanical stresses that govern the structural integrity of bimetallic components. Systematic reduction and sintering experiments will be used to characterize dimensional changes and densification behavior, while microstructural characterization will evaluate interfacial bonding and failure mechanisms. Finite element simulations will investigate the development of residual stresses and plastic deformation during cooling, providing insight into the influence of material property and geometry. These findings will guide strategies for paste formulation, heat treatment, and bimetallic interface design to minimize differential shrinkage, residual stresses and delamination. This work seeks to establish a framework for reliable fabrication of near-net-shape bimetallic steel components, advancing hydrogen-based steel manufacturing. Committee 

• Prof. Josh Kacher – School of Materials Science and Engineering (advisor) 
• Prof. Naresh Thadhani– School of Materials Science and Engineering 
• Prof. Preet Singh – School of Materials Science and Engineering
• Prof. Chaitanya Deo – School of Mechanical Engineering 
• Dr. Jim Zimmermann – R&D, Applied Ceramics Inc.