Graduation Semester and Year
Fall 2024
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Materials Science and Engineering
Department
Materials Science and Engineering
First Advisor
Efstathios I. Meletis
Abstract
EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.
This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as electrolyte concentration, working voltage, processing time, working distance, working temperature, additives, and the amplitude and frequency of the power supply were systematically adjusted to optimize the EPP process. These parameters influence the phase formation, deposition rate, intermetallic layer thickness, and coating coverage of the synthesized intermetallic layers.
Based on the findings, this study demonstrates that EPP is capable of producing various Ti-Ni intermetallic phases at the top surface layer that if desired, can also be followed by a pure Ni top layer. Key EPP processing parameters were identified that control the composition, thickness, uniformity, and surface morphology of the intermetallic phases. A significant enhancement of the tribological properties of Ti-6Al-4V was accomplished by the presence of the intermetallic surface layer. Surface modification via EPP processing resulted in a 148.25% increase in hardness, an 86.43% reduction in wear rate, and a 31.20% decrease in the coefficient of friction.
Keywords
Electrolytic Plasma Processing, Ti and Ti alloys, Ni-Ti intermetallics, Tribology
Disciplines
Metallurgy | Other Materials Science and Engineering | Tribology
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Zhang, Chuzhong, "SYNTHESIS OF Ni-BASED INTERMETALLICS BY ELECTROLYTIC PLASMA PROCESSING OF Ti AND Ti-BASED ALLOYS" (2024). Material Science and Engineering Dissertations. 128.
https://mavmatrix.uta.edu/materialscieng_dissertations/128