Author ORCID Identifier
Semester
Fall
Date of Graduation
2024
Document Type
Dissertation
Degree Type
PhD
College
Statler College of Engineering and Mineral Resources
Department
Industrial and Managements Systems Engineering
Committee Chair
Zhichao Liu, Ph.D.
Committee Member
Xueyan Song, Ph.D.
Committee Member
Imtiaz Ahmed, Ph.D.
Committee Member
Thorsten Wuest, Ph.D.
Committee Member
Sougata Roy, Ph.D.
Abstract
The increasing performance requirements of modern industrial systems, coupled with the imperative for decarbonization, necessitate a fundamental rethinking of metallic component design and manufacturing. Traditional materials, with their inherent limitations in property optimization, susceptibility to degradation, and weight constraints, are proving insufficient. Multi-material joining offers a potential solution, enabling designers to strategically integrate diverse materials with specific, tailored properties into single component. Functionally graded materials (FGMs) and oxide dispersion strengthened (ODS) materials are prime examples of this approach, delivering substantial improvements in wear resistance, thermal regulation, high-temperature resilience, and overall weight efficiency. However, conventional manufacturing approaches further exacerbate the limitations of single-material systems, typically leading to residual stresses, porosity, and difficulties when joining materials with dissimilar properties, resulting in interfacial defects and bonding inconsistencies.
Laser powder feed–directed energy deposition (L-DED), a promising additive manufacturing technology, facilitates multi-material fabrication through rapid melting and solidification, creating strong metallurgical bonds with minimal stress and distortion. This research leverages L-DED technology to pioneer two transformative pathways in multi-material engineering.
The first pathway explores a steep or bimetallic FGM manipulation to enhance thermo-electrical and wear resistance properties of L-DED as-deposited Inconel 718 (IN718), a nickel-based superalloy. A selective alloy coating is deposited through optimized process parameters to create strong, defect-free interfacial bonds aided by Marangoni convection effects. For thermal-cooling and electro-magnetic resistance applications, a copper alloy (CuSn10) is deposited onto IN718 via interlayer machining, functionalizing its performance for aerospace, power-generation and marine applications. Additionally, a cobalt alloy is integrated to IN718’s thermal-fatigue and wear resistance, enabling its application for high-temperature and multiphase flow characteristic of demanding industrial systems. The resulting FGM’s interfacial bonding region properties were characterized by assessing its thermo-electrical, and mechanical responses in conjunction with detailed microstructural and phase characterization studies, benchmarked against those of the original alloys.
The second pathway investigates a cutting-edge powder processing technique called mechano-chemical bonding (MCB) for embedding nano-oxides uniformly into SS316L (stainless steel alloy), producing ODS materials. Renowned for their high-temperature strength, resistance to void swelling, and durability against neutron irradiation, ODS materials serve critical roles in Gen-IV reactors’ infrastructure. Through varied Y₂O₃ concentrations, this study assessed their effects on microstructure stability, mechanical properties, and phase transformations in as-deposited ODS SS 316L and SS316L at constant energy density, tailoring the material for demanding applications.
By refining interfacial bonding characteristics through a comprehensive understanding of DED-induced microstructure evolution, phase transformations, as well as metallurgical properties, this research unlocks the full potential of multi-material systems. The findings pave the way for a sustainable, high-performance industrial future with robust, reliable components that meet the ever-evolving demands of the modern world.
Recommended Citation
Grandhi, Manikanta, "Laser Deposition Additive Manufacturing of Multi-Material and Metal-Ceramic Composite Structures" (2024). Graduate Theses, Dissertations, and Problem Reports. 12642.
https://researchrepository.wvu.edu/etd/12642
Included in
Industrial Engineering Commons, Manufacturing Commons, Nuclear Engineering Commons, Other Materials Science and Engineering Commons, Tribology Commons
