Characterization of Fe-W alloys electrodeposited from environmentally friendly electrolyte
Doctoral thesis, 2020
The results included in this thesis show that increasing the amount of co-deposited W in the coatings results in a transition from a nanocrystalline to a homogeneous amorphous structure, and to an increase in the thermal stability. In-situ TEM analyses on W-rich coatings (i.e. Fe24at.%W) revealed the formation of crystallites at 400 ℃ within the amorphous matrix. Moreover, a large fraction of the amorphous structure is still preserved upon annealing at 600 ℃, where alpha-Fe nanocrystals are found. The microstructural transformations result in an enhancement of mechanical properties of Fe-W coatings. The Fe-24at.%W coating is characterized with the highest hardness both in the as-deposited and annealed state, where a maximum value of 16.5 GPa is observed after annealing at 600 ℃. However, Fe-W coatings are characterized with rather low wear resistance due to severe tribo-oxidation resulting in high coefficient of friction (COF) and wear rates. A considerable improvement in the wear resistance is obtained with the co-deposition of 12vol.% of Al2O3 particles leading to a reduction in the COF and wear rate. The influence of the co-deposited alumina particles on the corrosion resistance is rather limited, i.e. similar values of the corrosion current are measured for the both the Fe-W/Al2O3 composites and Fe-W coatings. Annealing at 600 ℃ of Fe-W/12%Al2O3 composite leads to a combination of high hardness and high wear resistance which result superior to the hardness and wear resistance of hard chromium coatings.
Chalmers, Industrial and Materials Science, Materials and manufacture
In-depth characterization of as-deposited and annealed Fe-Wcoatings electrodeposited from glycolate-citrate plating bath
Electrochimica Acta,; Vol. 261(2018)p. 167-177
Enhanced mechanical properties and microstructural modifications in electrodeposited Fe-W alloys through controlled heat treatments
Surface and Coatings Technology,; Vol. 350(2018)p. 20-30
Improvement in the Wear Resistance under Dry Friction of Electrodeposited Fe-W Coatings through Heat Treatments
Coatings,; (2019)p. 66-
Nanocrystalline Electrodeposited Fe-W/Al2O3 Composites: Effect of Alumina Sub-microparticles on the Mechanical, Tribological, and Corrosion Properties
Frontiers in Chemistry,; Vol. 7(2019)p. 241-
Effect of heat treatments on the mechanical and tribological properties of electrodeposited Fe–W/Al<inf>2</inf>O<inf>3</inf> composites
Wear,; Vol. 448-449(2020)
A. Mulone, J. Hildenbrand, U. Klement-Electrodeposition: three steps toward sustainability
A. Mulone, I. Ennenb, A. Hüttenb, U. Klement-In-situ TEM annealing of amorphous Fe-24at.%W coatings and the effect of crystallization on hardness
This thesis studies iron-based coatings which are electrodeposited using a sustainable electrolyte: minimally aggressive, thermodynamically stable, and without toxic compounds. The aim of this work is to understand how the composition of the iron-based coatings influences the microstructure and the properties of interest: mechanical, wear and corrosion properties. Heat treatments are performed to optimize both the mechanical performance and the wear resistance of the iron-based coatings, which are compared to the properties of chrome coatings. The promising results presented in this thesis represent an important step toward the application of competitive and sustainable alternatives for coatings produced by environmentally hazardous processes.
Smart ELECTrodeposited Alloys for environmentally sustainable applications: from advanced protective coatings to micro/nano-robotic platforms (SELECTA)
European Commission (Horizon 2020), 2015-01-01 -- 2018-12-31.
Manufacturing, Surface and Joining Technology
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4723
Chalmers University of Technology
Virtual Development Laboratory (VDL), Chalmers Tvärgata 4C, Gothenburg
Opponent: Professor Peter Leisner, Jönköping University, Sweden