2, Birmingham City University, Birmingham, , United Kingdom
3, NASA Goddard Space Flight Center, Greenbelt, Maryland, United States
A high-speed electrodeposition regime that enables nanocrystalline nickel (Ni), cobalt (Co) and alloy (Ni-Co) film depositions with excellent adhesion characteristics on untreated titanium (Ti) surfaces was recently reported by our group . This was the first report of strong adhesion to an untreated Ti surface without any pretreatment, displacement reaction, or intermediate layer pre-deposition to mitigate the thin tenacious oxide that renders adhesion to Ti a challenge. Under conditions that combined the high flow rate electrodeposition with a higher current density than previously investigated, a new and additional mechanism was enabled that resulted in the growth of highly crystalline Ni, Co and Ni-Co nanowires in addition to the nanocrystalline film. Excellent quality nanowires for high melting point metals are difficult to grow using the standard electrodeposition into nanoporous anodized aluminium templates method [2,3]. The new template-less growth conditions reported here indicate that an alternative method to produce highly crystalline nanowires for high melting point metals has been identified. Novel roles for oxygen, carbon and chlorine chemistries in the nanocrystallite and nanowire growth processes are identified. We identify specific growth models for both nanocrystal and nanowire from quantitative TEM, SEM, SAED, EDS and AFM results.
 Hussain, MS. Direct Ni-Co alloy plating of titanium alloy surfaces by high speed electrodeposition. Trans Inst of Metal Finishing 90 (2012) 15. DOI: 10.1179/174591911X13188464808876
 H. Pan, B. Liu, J. Yi, C. Poh, S. Lim, J. Ding, Y. Feng, C.H.A. Huan, J. Lin. Growth of Single-Crystalline Ni and Co Nanowires via Electrochemical Deposition and Their Magnetic Properties. J. Phys. Chem. B 109 (2005) 3094-3098. DOI: 10.1021/jp0451997
 L.A. Meier, A.E. Alvarez, S.G. García, M.C. del Barrio. Formation of Cu and Ni Nanowires by Electrodeposition. Procedia Materials Science 8 (2015) 617-622. DOI: 10.1016/j.mspro.2015.04.116